Готовая лабораторная 4 по СУБД

BulletinBoard/BulletinBoard.sln

@@ -0,0 +1,25 @@
+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio Version 17
+VisualStudioVersion = 17.9.34622.214
+MinimumVisualStudioVersion = 10.0.40219.1
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "BulletinBoard", "BulletinBoard\BulletinBoard.csproj", "{262F1FD4-C5DD-42F3-B47A-8CB10414C3DE}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Any CPU = Debug|Any CPU
+		Release|Any CPU = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{262F1FD4-C5DD-42F3-B47A-8CB10414C3DE}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{262F1FD4-C5DD-42F3-B47A-8CB10414C3DE}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{262F1FD4-C5DD-42F3-B47A-8CB10414C3DE}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{262F1FD4-C5DD-42F3-B47A-8CB10414C3DE}.Release|Any CPU.Build.0 = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+	GlobalSection(ExtensibilityGlobals) = postSolution
+		SolutionGuid = {66435ADB-84E8-4E5D-9E06-34B5125842AE}
+	EndGlobalSection
+EndGlobal

BulletinBoard/BulletinBoard/AbstractManagmentDatabase.cs

@@ -0,0 +1,23 @@
+using System;
+using System.Collections.Generic;
+using System.Data;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace WebsiteForPlacingAds
+{
+    public abstract class AbstractManagmentDatabase
+    {
+        public abstract DataTable getEntryById(string tableName, int id);
+        public abstract Object getRowTableById(string tableName, string columnName, int id);
+        public abstract Object getRowTableById(DataTable table, string columnName, int i);
+        public abstract void ExecuteNonQuery(string query);
+        public abstract DataTable ExecuteQuery(string query);
+        public abstract DataTable getAllEntry(string tableName);
+        public abstract void insertInto(string tableName, params string[] values);
+        public abstract void deleteEntry(string tableName, int id);
+        public abstract void deleteEntry(string tableName, string name);
+        public abstract void reduceSeq(string seq, int currval);
+    }
+}

BulletinBoard/BulletinBoard/AdsForm/CreateAdsForm.Designer.cs

@@ -0,0 +1,274 @@
+namespace WebsiteForPlacingAds
+{
+    partial class CreateAdsForm
+    {
+        /// <summary>
+        ///  Required designer variable.
+        /// </summary>
+        private System.ComponentModel.IContainer components = null;
+
+        /// <summary>
+        ///  Clean up any resources being used.
+        /// </summary>
+        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
+        protected override void Dispose(bool disposing)
+        {
+            if (disposing && (components != null))
+            {
+                components.Dispose();
+            }
+            base.Dispose(disposing);
+        }
+
+        #region Windows Form Designer generated code
+
+        /// <summary>
+        ///  Required method for Designer support - do not modify
+        ///  the contents of this method with the code editor.
+        /// </summary>
+        private void InitializeComponent()
+        {
+            buttonCreateAd = new Button();
+            labelHeading = new Label();
+            textBoxHeading = new TextBox();
+            textBoxPrice = new TextBox();
+            labelPrice = new Label();
+            textBoxDate = new TextBox();
+            labelDate = new Label();
+            labelSubcategory = new Label();
+            labelCategory = new Label();
+            textBoxStatus = new TextBox();
+            labelStatus = new Label();
+            labelClient = new Label();
+            comboBoxSubcategory = new ComboBox();
+            comboBoxCategory = new ComboBox();
+            comboBoxClient = new ComboBox();
+            label1 = new Label();
+            comboBoxCity = new ComboBox();
+            label2 = new Label();
+            comboBoxRegion = new ComboBox();
+            SuspendLayout();
+            // 
+            // buttonCreateAd
+            // 
+            buttonCreateAd.Location = new Point(43, 443);
+            buttonCreateAd.Margin = new Padding(3, 2, 3, 2);
+            buttonCreateAd.Name = "buttonCreateAd";
+            buttonCreateAd.Size = new Size(239, 29);
+            buttonCreateAd.TabIndex = 0;
+            buttonCreateAd.Text = "Разместить объявление";
+            buttonCreateAd.UseVisualStyleBackColor = true;
+            buttonCreateAd.Click += buttonCreateAd_Click;
+            // 
+            // labelHeading
+            // 
+            labelHeading.AutoSize = true;
+            labelHeading.Location = new Point(43, 8);
+            labelHeading.Name = "labelHeading";
+            labelHeading.Size = new Size(65, 15);
+            labelHeading.TabIndex = 1;
+            labelHeading.Text = "Заголовок";
+            // 
+            // textBoxHeading
+            // 
+            textBoxHeading.Location = new Point(43, 26);
+            textBoxHeading.Margin = new Padding(3, 2, 3, 2);
+            textBoxHeading.Name = "textBoxHeading";
+            textBoxHeading.Size = new Size(239, 23);
+            textBoxHeading.TabIndex = 2;
+            // 
+            // textBoxPrice
+            // 
+            textBoxPrice.Location = new Point(43, 72);
+            textBoxPrice.Margin = new Padding(3, 2, 3, 2);
+            textBoxPrice.Name = "textBoxPrice";
+            textBoxPrice.Size = new Size(239, 23);
+            textBoxPrice.TabIndex = 4;
+            // 
+            // labelPrice
+            // 
+            labelPrice.AutoSize = true;
+            labelPrice.Location = new Point(43, 55);
+            labelPrice.Name = "labelPrice";
+            labelPrice.Size = new Size(35, 15);
+            labelPrice.TabIndex = 3;
+            labelPrice.Text = "Цена";
+            // 
+            // textBoxDate
+            // 
+            textBoxDate.Location = new Point(43, 118);
+            textBoxDate.Margin = new Padding(3, 2, 3, 2);
+            textBoxDate.Name = "textBoxDate";
+            textBoxDate.Size = new Size(239, 23);
+            textBoxDate.TabIndex = 6;
+            // 
+            // labelDate
+            // 
+            labelDate.AutoSize = true;
+            labelDate.Location = new Point(43, 101);
+            labelDate.Name = "labelDate";
+            labelDate.Size = new Size(105, 15);
+            labelDate.TabIndex = 5;
+            labelDate.Text = "Дата размещения";
+            // 
+            // labelSubcategory
+            // 
+            labelSubcategory.AutoSize = true;
+            labelSubcategory.Location = new Point(43, 292);
+            labelSubcategory.Name = "labelSubcategory";
+            labelSubcategory.Size = new Size(84, 15);
+            labelSubcategory.TabIndex = 11;
+            labelSubcategory.Text = "Подкатегория";
+            // 
+            // labelCategory
+            // 
+            labelCategory.AutoSize = true;
+            labelCategory.Location = new Point(43, 246);
+            labelCategory.Name = "labelCategory";
+            labelCategory.Size = new Size(63, 15);
+            labelCategory.TabIndex = 9;
+            labelCategory.Text = "Категория";
+            // 
+            // textBoxStatus
+            // 
+            textBoxStatus.Location = new Point(43, 166);
+            textBoxStatus.Margin = new Padding(3, 2, 3, 2);
+            textBoxStatus.Name = "textBoxStatus";
+            textBoxStatus.Size = new Size(239, 23);
+            textBoxStatus.TabIndex = 8;
+            // 
+            // labelStatus
+            // 
+            labelStatus.AutoSize = true;
+            labelStatus.Location = new Point(43, 148);
+            labelStatus.Name = "labelStatus";
+            labelStatus.Size = new Size(43, 15);
+            labelStatus.TabIndex = 7;
+            labelStatus.Text = "Статус";
+            // 
+            // labelClient
+            // 
+            labelClient.AutoSize = true;
+            labelClient.Location = new Point(43, 196);
+            labelClient.Name = "labelClient";
+            labelClient.Size = new Size(46, 15);
+            labelClient.TabIndex = 13;
+            labelClient.Text = "Клиент";
+            // 
+            // comboBoxSubcategory
+            // 
+            comboBoxSubcategory.FormattingEnabled = true;
+            comboBoxSubcategory.Location = new Point(43, 310);
+            comboBoxSubcategory.Margin = new Padding(3, 2, 3, 2);
+            comboBoxSubcategory.Name = "comboBoxSubcategory";
+            comboBoxSubcategory.Size = new Size(239, 23);
+            comboBoxSubcategory.TabIndex = 15;
+            // 
+            // comboBoxCategory
+            // 
+            comboBoxCategory.FormattingEnabled = true;
+            comboBoxCategory.Location = new Point(43, 263);
+            comboBoxCategory.Margin = new Padding(3, 2, 3, 2);
+            comboBoxCategory.Name = "comboBoxCategory";
+            comboBoxCategory.Size = new Size(239, 23);
+            comboBoxCategory.TabIndex = 16;
+            // 
+            // comboBoxClient
+            // 
+            comboBoxClient.FormattingEnabled = true;
+            comboBoxClient.Location = new Point(43, 213);
+            comboBoxClient.Margin = new Padding(3, 2, 3, 2);
+            comboBoxClient.Name = "comboBoxClient";
+            comboBoxClient.Size = new Size(239, 23);
+            comboBoxClient.TabIndex = 17;
+            // 
+            // label1
+            // 
+            label1.AutoSize = true;
+            label1.Location = new Point(43, 341);
+            label1.Name = "label1";
+            label1.Size = new Size(46, 15);
+            label1.TabIndex = 22;
+            label1.Text = "Регион";
+            // 
+            // comboBoxCity
+            // 
+            comboBoxCity.FormattingEnabled = true;
+            comboBoxCity.Location = new Point(43, 400);
+            comboBoxCity.Margin = new Padding(3, 2, 3, 2);
+            comboBoxCity.Name = "comboBoxCity";
+            comboBoxCity.Size = new Size(239, 23);
+            comboBoxCity.TabIndex = 23;
+            // 
+            // label2
+            // 
+            label2.AutoSize = true;
+            label2.Location = new Point(43, 384);
+            label2.Name = "label2";
+            label2.Size = new Size(40, 15);
+            label2.TabIndex = 24;
+            label2.Text = "Город";
+            // 
+            // comboBoxRegion
+            // 
+            comboBoxRegion.FormattingEnabled = true;
+            comboBoxRegion.Location = new Point(43, 359);
+            comboBoxRegion.Margin = new Padding(3, 2, 3, 2);
+            comboBoxRegion.Name = "comboBoxRegion";
+            comboBoxRegion.Size = new Size(239, 23);
+            comboBoxRegion.TabIndex = 25;
+            // 
+            // CreateAdsForm
+            // 
+            AutoScaleDimensions = new SizeF(7F, 15F);
+            AutoScaleMode = AutoScaleMode.Font;
+            ClientSize = new Size(324, 483);
+            Controls.Add(label2);
+            Controls.Add(label1);
+            Controls.Add(comboBoxRegion);
+            Controls.Add(comboBoxCity);
+            Controls.Add(comboBoxClient);
+            Controls.Add(comboBoxCategory);
+            Controls.Add(comboBoxSubcategory);
+            Controls.Add(labelClient);
+            Controls.Add(labelSubcategory);
+            Controls.Add(labelCategory);
+            Controls.Add(textBoxStatus);
+            Controls.Add(labelStatus);
+            Controls.Add(textBoxDate);
+            Controls.Add(labelDate);
+            Controls.Add(textBoxPrice);
+            Controls.Add(labelPrice);
+            Controls.Add(textBoxHeading);
+            Controls.Add(labelHeading);
+            Controls.Add(buttonCreateAd);
+            Margin = new Padding(3, 2, 3, 2);
+            Name = "CreateAdsForm";
+            Text = "Объявления";
+            ResumeLayout(false);
+            PerformLayout();
+        }
+
+        #endregion
+
+        private Button buttonCreateAd;
+        private Label labelHeading;
+        private TextBox textBoxHeading;
+        private TextBox textBoxPrice;
+        private Label labelPrice;
+        private TextBox textBoxDate;
+        private Label labelDate;
+        private Label labelSubcategory;
+        private Label labelCategory;
+        private TextBox textBoxStatus;
+        private Label labelStatus;
+        private Label labelClient;
+        private ComboBox comboBoxSubcategory;
+        private ComboBox comboBoxCategory;
+        private ComboBox comboBoxClient;
+        private Label label1;
+        private ComboBox comboBoxRegion;
+        private Label label2;
+        private ComboBox comboBoxCity;
+    }
+}

BulletinBoard/BulletinBoard/AdsForm/CreateAdsForm.cs

@@ -0,0 +1,103 @@
+using System.Data;
+
+namespace WebsiteForPlacingAds
+{
+    public partial class CreateAdsForm : Form
+    {
+        AbstractManagmentDatabase managmentDatabase;
+        public CreateAdsForm(AbstractManagmentDatabase managmentDatabase)
+        {
+            InitializeComponent();
+            this.managmentDatabase = managmentDatabase;
+            LoadData();
+        }
+
+        private void buttonCreateAd_Click(object sender, EventArgs e)
+        {
+            string[] client = comboBoxClient.SelectedItem.ToString().Split(" ");
+            string[] category = comboBoxCategory.SelectedItem.ToString().Split(" ");
+            string[] subcategory = comboBoxSubcategory.SelectedItem.ToString().Split(" ");
+            string[] region = comboBoxCategory.SelectedItem.ToString().Split(" ");
+            string[] city = comboBoxSubcategory.SelectedItem.ToString().Split(" ");
+
+            string heading = textBoxHeading.Text;
+            string price = textBoxPrice.Text;
+            string date = textBoxDate.Text;
+            string status = textBoxStatus.Text;
+            string client_id = client[0];
+            string category_id = category[0];
+            string subcategory_id = subcategory[0];
+            string region_id = region[0];
+            string city_id = city[0];
+
+            try
+            {
+                DateTime start = DateTime.Now;
+
+                managmentDatabase.insertInto("ads", $"'{heading}'", price, $"'{date}'", $"'{status}'", client_id, category_id, subcategory_id, region_id, city_id);
+                MessageBox.Show("Äîáàâëåíî!");
+                LoadData();
+
+                DateTime end = DateTime.Now;
+                TimeSpan duration = end - start;
+                MessageBox.Show($"Äîáàâëåíî! Âðåìÿ âûïîëíåíèÿ: {duration.TotalMilliseconds} ìñ");
+
+                // Çàêðûòü òåêóùóþ ôîðìó ïîñëå âûïîëíåíèÿ äåéñòâèé
+                this.Close();
+            }
+            catch (Exception ex)
+            {
+                MessageBox.Show("Íå óäàëîñü äîáàâèòü");
+            }
+        }
+
+        private void LoadData()
+        {
+            comboBoxCategory.Items.Clear();
+            comboBoxSubcategory.Items.Clear();
+            comboBoxClient.Items.Clear();
+            comboBoxRegion.Items.Clear();
+            comboBoxCity.Items.Clear();
+            DataTable result = managmentDatabase.getAllEntry("CATEGORIES");
+            string[] id_names = new string[result.Rows.Count];
+            for (int i = 0; i < result.Rows.Count; i++)
+            {
+                id_names[i] = managmentDatabase.getRowTableById(result, "categories_id", i).ToString() + ". " + managmentDatabase.getRowTableById(result, "name", i).ToString();
+                comboBoxCategory.Items.Add(id_names[i]);
+            }
+
+            result = managmentDatabase.getAllEntry("SUBCATEGORIES");
+            id_names = new string[result.Rows.Count];
+            for (int i = 0; i < result.Rows.Count; i++)
+            {
+                id_names[i] = managmentDatabase.getRowTableById(result, "subcategories_id", i).ToString() + ". " + managmentDatabase.getRowTableById(result, "name", i).ToString();
+                comboBoxSubcategory.Items.Add(id_names[i]);
+            }
+
+            result = managmentDatabase.getAllEntry("CLIENTS");
+            string[] id_names_surnames = new string[result.Rows.Count];
+            for (int i = 0; i < result.Rows.Count; i++)
+            {
+                id_names_surnames[i] = managmentDatabase.getRowTableById(result, "clients_id", i).ToString().Trim() + ". " + managmentDatabase.getRowTableById(result, "name", i).ToString().Trim() + " " + managmentDatabase.getRowTableById(result, "surname", i).ToString().Trim();
+                comboBoxClient.Items.Add(id_names_surnames[i]);
+            }
+
+            result = managmentDatabase.getAllEntry("REGIONS");
+            id_names = new string[result.Rows.Count];
+            for (int i = 0; i < result.Rows.Count; i++)
+            {
+                id_names[i] = managmentDatabase.getRowTableById(result, "regions_id", i).ToString() + ". " + managmentDatabase.getRowTableById(result, "name", i).ToString();
+                comboBoxRegion.Items.Add(id_names[i]);
+            }
+
+ 
+            result = managmentDatabase.getAllEntry("CITIES");
+            id_names = new string[result.Rows.Count];
+            for (int i = 0; i < result.Rows.Count; i++)
+            {
+                id_names[i] = managmentDatabase.getRowTableById(result, "cities_id", i).ToString() + ". " + managmentDatabase.getRowTableById(result, "name", i).ToString();
+                comboBoxCity.Items.Add(id_names[i]);
+            }
+        }
+    }
+}

BulletinBoard/BulletinBoard/AdsForm/CreateAdsForm.resx

@@ -0,0 +1,120 @@
+<?xml version="1.0" encoding="utf-8"?>
+<root>
+  <!--
+    Microsoft ResX Schema 
+
+    Version 2.0
+
+    The primary goals of this format is to allow a simple XML format
+    that is mostly human readable. The generation and parsing of the
+    various data types are done through the TypeConverter classes
+    associated with the data types.
+
+    Example:
+
+    ... ado.net/XML headers & schema ...
+    <resheader name="resmimetype">text/microsoft-resx</resheader>
+    <resheader name="version">2.0</resheader>
+    <resheader name="reader">System.Resources.ResXResourceReader, System.Windows.Forms, ...</resheader>
+    <resheader name="writer">System.Resources.ResXResourceWriter, System.Windows.Forms, ...</resheader>
+    <data name="Name1"><value>this is my long string</value><comment>this is a comment</comment></data>
+    <data name="Color1" type="System.Drawing.Color, System.Drawing">Blue</data>
+    <data name="Bitmap1" mimetype="application/x-microsoft.net.object.binary.base64">
+        <value>[base64 mime encoded serialized .NET Framework object]</value>
+    </data>
+    <data name="Icon1" type="System.Drawing.Icon, System.Drawing" mimetype="application/x-microsoft.net.object.bytearray.base64">
+        <value>[base64 mime encoded string representing a byte array form of the .NET Framework object]</value>
+        <comment>This is a comment</comment>
+    </data>
+
+    There are any number of "resheader" rows that contain simple
+    name/value pairs.
+
+    Each data row contains a name, and value. The row also contains a
+    type or mimetype. Type corresponds to a .NET class that support
+    text/value conversion through the TypeConverter architecture.
+    Classes that don't support this are serialized and stored with the
+    mimetype set.
+
+    The mimetype is used for serialized objects, and tells the
+    ResXResourceReader how to depersist the object. This is currently not
+    extensible. For a given mimetype the value must be set accordingly:
+
+    Note - application/x-microsoft.net.object.binary.base64 is the format
+    that the ResXResourceWriter will generate, however the reader can
+    read any of the formats listed below.
+
+    mimetype: application/x-microsoft.net.object.binary.base64
+    value   : The object must be serialized with
+            : System.Runtime.Serialization.Formatters.Binary.BinaryFormatter
+            : and then encoded with base64 encoding.
+    
+    mimetype: application/x-microsoft.net.object.soap.base64
+    value   : The object must be serialized with
+            : System.Runtime.Serialization.Formatters.Soap.SoapFormatter
+            : and then encoded with base64 encoding.
+
+    mimetype: application/x-microsoft.net.object.bytearray.base64
+    value   : The object must be serialized into a byte array
+            : using a System.ComponentModel.TypeConverter
+            : and then encoded with base64 encoding.
+    -->
+  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
+    <xsd:import namespace="http://www.w3.org/XML/1998/namespace" />
+    <xsd:element name="root" msdata:IsDataSet="true">
+      <xsd:complexType>
+        <xsd:choice maxOccurs="unbounded">
+          <xsd:element name="metadata">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" />
+              </xsd:sequence>
+              <xsd:attribute name="name" use="required" type="xsd:string" />
+              <xsd:attribute name="type" type="xsd:string" />
+              <xsd:attribute name="mimetype" type="xsd:string" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="assembly">
+            <xsd:complexType>
+              <xsd:attribute name="alias" type="xsd:string" />
+              <xsd:attribute name="name" type="xsd:string" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="data">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" msdata:Ordinal="1" />
+              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />
+              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="resheader">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" />
+            </xsd:complexType>
+          </xsd:element>
+        </xsd:choice>
+      </xsd:complexType>
+    </xsd:element>
+  </xsd:schema>
+  <resheader name="resmimetype">
+    <value>text/microsoft-resx</value>
+  </resheader>
+  <resheader name="version">
+    <value>2.0</value>
+  </resheader>
+  <resheader name="reader">
+    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+  <resheader name="writer">
+    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+</root>

BulletinBoard/BulletinBoard/AdsForm/DeleteAdsForm.Designer.cs

@@ -0,0 +1,84 @@
+namespace WebsiteForPlacingAds
+{
+    partial class DeleteAdsForm
+    {
+        /// <summary>
+        /// Required designer variable.
+        /// </summary>
+        private System.ComponentModel.IContainer components = null;
+
+        /// <summary>
+        /// Clean up any resources being used.
+        /// </summary>
+        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
+        protected override void Dispose(bool disposing)
+        {
+            if (disposing && (components != null))
+            {
+                components.Dispose();
+            }
+            base.Dispose(disposing);
+        }
+
+        #region Windows Form Designer generated code
+
+        /// <summary>
+        /// Required method for Designer support - do not modify
+        /// the contents of this method with the code editor.
+        /// </summary>
+        private void InitializeComponent()
+        {
+            this.label1 = new System.Windows.Forms.Label();
+            this.buttonDeleteAd = new System.Windows.Forms.Button();
+            this.comboBoxDeleteAds = new System.Windows.Forms.ComboBox();
+            this.SuspendLayout();
+            // 
+            // label1
+            // 
+            this.label1.AutoSize = true;
+            this.label1.Location = new System.Drawing.Point(80, 22);
+            this.label1.Name = "label1";
+            this.label1.Size = new System.Drawing.Size(338, 20);
+            this.label1.TabIndex = 0;
+            this.label1.Text = "Выберите объявление, которое хотите удалить";
+            // 
+            // buttonDeleteAd
+            // 
+            this.buttonDeleteAd.Location = new System.Drawing.Point(151, 113);
+            this.buttonDeleteAd.Name = "buttonDeleteAd";
+            this.buttonDeleteAd.Size = new System.Drawing.Size(186, 37);
+            this.buttonDeleteAd.TabIndex = 1;
+            this.buttonDeleteAd.Text = "Удалить";
+            this.buttonDeleteAd.UseVisualStyleBackColor = true;
+            this.buttonDeleteAd.Click += new System.EventHandler(this.buttonDeleteAd_Click);
+            // 
+            // comboBoxDeleteAds
+            // 
+            this.comboBoxDeleteAds.FormattingEnabled = true;
+            this.comboBoxDeleteAds.Location = new System.Drawing.Point(40, 64);
+            this.comboBoxDeleteAds.Name = "comboBoxDeleteAds";
+            this.comboBoxDeleteAds.Size = new System.Drawing.Size(419, 28);
+            this.comboBoxDeleteAds.TabIndex = 2;
+            // 
+            // DeleteAdsForm
+            // 
+            this.AutoScaleDimensions = new System.Drawing.SizeF(8F, 20F);
+            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
+            this.ClientSize = new System.Drawing.Size(505, 175);
+            this.Controls.Add(this.comboBoxDeleteAds);
+            this.Controls.Add(this.buttonDeleteAd);
+            this.Controls.Add(this.label1);
+            this.Name = "DeleteAdsForm";
+            this.Text = "Удалить объявление";
+            this.ResumeLayout(false);
+            this.PerformLayout();
+
+        }
+
+        #endregion
+
+        private Label label1;
+        private Button buttonDeleteAd;
+        private ComboBox comboBoxDeleteAds;
+    }
+}

BulletinBoard/BulletinBoard/AdsForm/DeleteAdsForm.cs

@@ -0,0 +1,71 @@
+using System;
+using System.Collections.Generic;
+using System.ComponentModel;
+using System.Data;
+using System.Drawing;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using System.Windows.Forms;
+
+namespace WebsiteForPlacingAds
+{
+    public partial class DeleteAdsForm : Form
+    {
+        AbstractManagmentDatabase managmentDatabase;
+        private int setval_seq;
+        public DeleteAdsForm(AbstractManagmentDatabase managmentDatabase)
+        {
+            InitializeComponent();
+            this.managmentDatabase = managmentDatabase;
+            LoadData();
+        }
+        
+        private void buttonDeleteAd_Click(object sender, EventArgs e)
+        {
+            string[] ads = comboBoxDeleteAds.SelectedItem.ToString().Split("|");
+            string ad_id = ads[0].Trim();
+            string query = $"DELETE FROM ADS WHERE ads_id = {ad_id}";
+            string query_seq_reduction = $"SELECT setval('seq_ads', {setval_seq - 1});";
+            try
+            {
+                DateTime start = DateTime.Now;
+
+                managmentDatabase.deleteEntry("ads", int.Parse(ad_id));
+                if (setval_seq > 0) managmentDatabase.reduceSeq("seq_ads", setval_seq);
+                MessageBox.Show("Удалено!");
+                LoadData();
+
+                DateTime end = DateTime.Now;
+                TimeSpan duration = end - start;
+                MessageBox.Show($"Добавлено! Время выполнения: {duration.TotalMilliseconds} мс");
+            }
+            catch (Exception ex)
+            {
+                MessageBox.Show("Не удалось удалить");
+            }
+        }
+        public void LoadData()
+        {
+            comboBoxDeleteAds.Items.Clear();
+            DataTable result = managmentDatabase.getAllEntry("ADS");
+            setval_seq = result.Rows.Count;
+            string Ads = "";
+            for (int i = 0; i < result.Rows.Count; i++)
+            {
+                setval_seq = Math.Max(Convert.ToInt32(managmentDatabase.getRowTableById(result, "ads_id", i)), setval_seq);
+                Ads = managmentDatabase.getRowTableById(result, "ads_id", i).ToString() + " | " +
+                                managmentDatabase.getRowTableById(result, "heading", i).ToString() + " | " +
+                                managmentDatabase.getRowTableById(result, "price", i).ToString() + " | " +
+                                ((DateTime)managmentDatabase.getRowTableById(result, "date_of_placement", i)).ToString("dd.MM.yyy") + " | " +
+                                managmentDatabase.getRowTableById(result, "status", i).ToString() + " | " +
+                                managmentDatabase.getRowTableById(result, "client_id", i).ToString() + " | " +
+                                managmentDatabase.getRowTableById(result, "category_id", i).ToString() + " | " +
+                                managmentDatabase.getRowTableById(result, "subcategory_id", i).ToString() + " | " +
+                                managmentDatabase.getRowTableById(result, "region_id", i).ToString() + " | " +
+                                managmentDatabase.getRowTableById(result, "city_id", i).ToString() + "\n";
+                comboBoxDeleteAds.Items.Add(Ads);
+            }
+        }
+    }
+}

BulletinBoard/BulletinBoard/AdsForm/DeleteAdsForm.resx

@@ -0,0 +1,60 @@
+<root>
+  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
+    <xsd:import namespace="http://www.w3.org/XML/1998/namespace" />
+    <xsd:element name="root" msdata:IsDataSet="true">
+      <xsd:complexType>
+        <xsd:choice maxOccurs="unbounded">
+          <xsd:element name="metadata">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" />
+              </xsd:sequence>
+              <xsd:attribute name="name" use="required" type="xsd:string" />
+              <xsd:attribute name="type" type="xsd:string" />
+              <xsd:attribute name="mimetype" type="xsd:string" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="assembly">
+            <xsd:complexType>
+              <xsd:attribute name="alias" type="xsd:string" />
+              <xsd:attribute name="name" type="xsd:string" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="data">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" msdata:Ordinal="1" />
+              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />
+              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="resheader">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" />
+            </xsd:complexType>
+          </xsd:element>
+        </xsd:choice>
+      </xsd:complexType>
+    </xsd:element>
+  </xsd:schema>
+  <resheader name="resmimetype">
+    <value>text/microsoft-resx</value>
+  </resheader>
+  <resheader name="version">
+    <value>2.0</value>
+  </resheader>
+  <resheader name="reader">
+    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+  <resheader name="writer">
+    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+</root>

BulletinBoard/BulletinBoard/AdsForm/ListAdsForm.Designer.cs

@@ -0,0 +1,74 @@
+namespace WebsiteForPlacingAds
+{
+    partial class ListAdsForm
+    {
+        /// <summary>
+        /// Required designer variable.
+        /// </summary>
+        private System.ComponentModel.IContainer components = null;
+
+        /// <summary>
+        /// Clean up any resources being used.
+        /// </summary>
+        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
+        protected override void Dispose(bool disposing)
+        {
+            if (disposing && (components != null))
+            {
+                components.Dispose();
+            }
+            base.Dispose(disposing);
+        }
+
+        #region Windows Form Designer generated code
+
+        /// <summary>
+        /// Required method for Designer support - do not modify
+        /// the contents of this method with the code editor.
+        /// </summary>
+        private void InitializeComponent()
+        {
+            this.label1 = new System.Windows.Forms.Label();
+            this.labelListAds = new System.Windows.Forms.Label();
+            this.SuspendLayout();
+            // 
+            // label1
+            // 
+            this.label1.AutoSize = true;
+            this.label1.BackColor = System.Drawing.SystemColors.Control;
+            this.label1.Font = new System.Drawing.Font("Segoe UI", 11F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point);
+            this.label1.Location = new System.Drawing.Point(12, 9);
+            this.label1.Name = "label1";
+            this.label1.Size = new System.Drawing.Size(186, 25);
+            this.label1.TabIndex = 0;
+            this.label1.Text = "Список объявлений";
+            // 
+            // labelListAds
+            // 
+            this.labelListAds.AutoSize = true;
+            this.labelListAds.Font = new System.Drawing.Font("Segoe UI", 10F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point);
+            this.labelListAds.Location = new System.Drawing.Point(12, 47);
+            this.labelListAds.Name = "labelListAds";
+            this.labelListAds.Size = new System.Drawing.Size(0, 23);
+            this.labelListAds.TabIndex = 1;
+            // 
+            // ListAdsForm
+            // 
+            this.AutoScaleDimensions = new System.Drawing.SizeF(8F, 20F);
+            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
+            this.ClientSize = new System.Drawing.Size(800, 450);
+            this.Controls.Add(this.labelListAds);
+            this.Controls.Add(this.label1);
+            this.Name = "ListAdsForm";
+            this.Text = "ListAdsForm";
+            this.ResumeLayout(false);
+            this.PerformLayout();
+
+        }
+
+        #endregion
+
+        private Label label1;
+        private Label labelListAds;
+    }
+}

BulletinBoard/BulletinBoard/AdsForm/ListAdsForm.cs

@@ -0,0 +1,50 @@
+using System;
+using System.Collections.Generic;
+using System.ComponentModel;
+using System.Data;
+using System.Drawing;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using System.Windows.Forms;
+using System.Windows.Forms.VisualStyles;
+
+namespace WebsiteForPlacingAds
+{
+    public partial class ListAdsForm : Form
+    {
+        AbstractManagmentDatabase managmentDatabase;
+        public ListAdsForm(AbstractManagmentDatabase managmentDatabase)
+        {
+            InitializeComponent();
+            this.managmentDatabase = managmentDatabase;
+            LoadData();
+        }
+
+        private void LoadData()
+        {
+            DateTime start = DateTime.Now;
+
+            DataTable result = managmentDatabase.getAllEntry("ADS");
+            string listAds = "";
+            for (int i = 0; i < result.Rows.Count; i++)
+            {
+                listAds += managmentDatabase.getRowTableById(result, "ads_id", i).ToString() + " | " +
+                                managmentDatabase.getRowTableById(result, "heading", i).ToString() + " | " +
+                                managmentDatabase.getRowTableById(result, "price", i).ToString() + " | " +
+                                ((DateTime)managmentDatabase.getRowTableById(result, "date_of_placement", i)).ToString("dd.MM.yyy") + " | " +
+                                managmentDatabase.getRowTableById(result, "status", i).ToString() + " | " +
+                                managmentDatabase.getRowTableById(result, "client_id", i).ToString() + " | " +
+                                managmentDatabase.getRowTableById(result, "category_id", i).ToString() + " | " +
+                                managmentDatabase.getRowTableById(result, "subcategory_id", i).ToString() + " | " +
+                                managmentDatabase.getRowTableById(result, "region_id", i).ToString() + " | " +
+                                managmentDatabase.getRowTableById(result, "city_id", i).ToString() + "\n";
+            }
+            labelListAds.Text = listAds;
+
+            DateTime end = DateTime.Now;
+            TimeSpan duration = end - start;
+            MessageBox.Show($"Список загружен! Время выполнения: {duration.TotalMilliseconds} мс");
+        }
+    }
+}

BulletinBoard/BulletinBoard/AdsForm/ListAdsForm.resx

@@ -0,0 +1,60 @@
+<root>
+  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
+    <xsd:import namespace="http://www.w3.org/XML/1998/namespace" />
+    <xsd:element name="root" msdata:IsDataSet="true">
+      <xsd:complexType>
+        <xsd:choice maxOccurs="unbounded">
+          <xsd:element name="metadata">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" />
+              </xsd:sequence>
+              <xsd:attribute name="name" use="required" type="xsd:string" />
+              <xsd:attribute name="type" type="xsd:string" />
+              <xsd:attribute name="mimetype" type="xsd:string" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="assembly">
+            <xsd:complexType>
+              <xsd:attribute name="alias" type="xsd:string" />
+              <xsd:attribute name="name" type="xsd:string" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="data">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" msdata:Ordinal="1" />
+              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />
+              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="resheader">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" />
+            </xsd:complexType>
+          </xsd:element>
+        </xsd:choice>
+      </xsd:complexType>
+    </xsd:element>
+  </xsd:schema>
+  <resheader name="resmimetype">
+    <value>text/microsoft-resx</value>
+  </resheader>
+  <resheader name="version">
+    <value>2.0</value>
+  </resheader>
+  <resheader name="reader">
+    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+  <resheader name="writer">
+    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+</root>

BulletinBoard/BulletinBoard/AdsForm/UpdateAdsForm.Designer.cs

@@ -0,0 +1,251 @@
+namespace WebsiteForPlacingAds
+{
+    partial class UpdateAdsForm
+    {
+        /// <summary>
+        /// Required designer variable.
+        /// </summary>
+        private System.ComponentModel.IContainer components = null;
+
+        /// <summary>
+        /// Clean up any resources being used.
+        /// </summary>
+        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
+        protected override void Dispose(bool disposing)
+        {
+            if (disposing && (components != null))
+            {
+                components.Dispose();
+            }
+            base.Dispose(disposing);
+        }
+
+        #region Windows Form Designer generated code
+
+        /// <summary>
+        /// Required method for Designer support - do not modify
+        /// the contents of this method with the code editor.
+        /// </summary>
+        private void InitializeComponent()
+        {
+            comboBoxClient = new ComboBox();
+            comboBoxCategory = new ComboBox();
+            comboBoxSubcategory = new ComboBox();
+            labelClient = new Label();
+            labelSubcategory = new Label();
+            labelCategory = new Label();
+            textBoxStatus = new TextBox();
+            labelStatus = new Label();
+            textBoxDate = new TextBox();
+            labelDate = new Label();
+            textBoxPrice = new TextBox();
+            labelPrice = new Label();
+            textBoxHeading = new TextBox();
+            labelHeading = new Label();
+            buttonUpdateAd = new Button();
+            label1 = new Label();
+            comboBoxUpdateAd = new ComboBox();
+            SuspendLayout();
+            // 
+            // comboBoxClient
+            // 
+            comboBoxClient.FormattingEnabled = true;
+            comboBoxClient.Location = new Point(81, 278);
+            comboBoxClient.Margin = new Padding(3, 2, 3, 2);
+            comboBoxClient.Name = "comboBoxClient";
+            comboBoxClient.Size = new Size(239, 23);
+            comboBoxClient.TabIndex = 32;
+            // 
+            // comboBoxCategory
+            // 
+            comboBoxCategory.FormattingEnabled = true;
+            comboBoxCategory.Location = new Point(81, 328);
+            comboBoxCategory.Margin = new Padding(3, 2, 3, 2);
+            comboBoxCategory.Name = "comboBoxCategory";
+            comboBoxCategory.Size = new Size(239, 23);
+            comboBoxCategory.TabIndex = 31;
+            // 
+            // comboBoxSubcategory
+            // 
+            comboBoxSubcategory.FormattingEnabled = true;
+            comboBoxSubcategory.Location = new Point(81, 375);
+            comboBoxSubcategory.Margin = new Padding(3, 2, 3, 2);
+            comboBoxSubcategory.Name = "comboBoxSubcategory";
+            comboBoxSubcategory.Size = new Size(239, 23);
+            comboBoxSubcategory.TabIndex = 30;
+            // 
+            // labelClient
+            // 
+            labelClient.AutoSize = true;
+            labelClient.Location = new Point(81, 261);
+            labelClient.Name = "labelClient";
+            labelClient.Size = new Size(46, 15);
+            labelClient.TabIndex = 29;
+            labelClient.Text = "Клиент";
+            // 
+            // labelSubcategory
+            // 
+            labelSubcategory.AutoSize = true;
+            labelSubcategory.Location = new Point(81, 358);
+            labelSubcategory.Name = "labelSubcategory";
+            labelSubcategory.Size = new Size(84, 15);
+            labelSubcategory.TabIndex = 28;
+            labelSubcategory.Text = "Подкатегория";
+            // 
+            // labelCategory
+            // 
+            labelCategory.AutoSize = true;
+            labelCategory.Location = new Point(81, 311);
+            labelCategory.Name = "labelCategory";
+            labelCategory.Size = new Size(63, 15);
+            labelCategory.TabIndex = 27;
+            labelCategory.Text = "Категория";
+            // 
+            // textBoxStatus
+            // 
+            textBoxStatus.Location = new Point(81, 231);
+            textBoxStatus.Margin = new Padding(3, 2, 3, 2);
+            textBoxStatus.Name = "textBoxStatus";
+            textBoxStatus.Size = new Size(239, 23);
+            textBoxStatus.TabIndex = 26;
+            // 
+            // labelStatus
+            // 
+            labelStatus.AutoSize = true;
+            labelStatus.Location = new Point(81, 214);
+            labelStatus.Name = "labelStatus";
+            labelStatus.Size = new Size(43, 15);
+            labelStatus.TabIndex = 25;
+            labelStatus.Text = "Статус";
+            // 
+            // textBoxDate
+            // 
+            textBoxDate.Location = new Point(81, 184);
+            textBoxDate.Margin = new Padding(3, 2, 3, 2);
+            textBoxDate.Name = "textBoxDate";
+            textBoxDate.Size = new Size(239, 23);
+            textBoxDate.TabIndex = 24;
+            // 
+            // labelDate
+            // 
+            labelDate.AutoSize = true;
+            labelDate.Location = new Point(81, 166);
+            labelDate.Name = "labelDate";
+            labelDate.Size = new Size(105, 15);
+            labelDate.TabIndex = 23;
+            labelDate.Text = "Дата размещения";
+            // 
+            // textBoxPrice
+            // 
+            textBoxPrice.Location = new Point(81, 137);
+            textBoxPrice.Margin = new Padding(3, 2, 3, 2);
+            textBoxPrice.Name = "textBoxPrice";
+            textBoxPrice.Size = new Size(239, 23);
+            textBoxPrice.TabIndex = 22;
+            // 
+            // labelPrice
+            // 
+            labelPrice.AutoSize = true;
+            labelPrice.Location = new Point(81, 120);
+            labelPrice.Name = "labelPrice";
+            labelPrice.Size = new Size(35, 15);
+            labelPrice.TabIndex = 21;
+            labelPrice.Text = "Цена";
+            // 
+            // textBoxHeading
+            // 
+            textBoxHeading.Location = new Point(81, 91);
+            textBoxHeading.Margin = new Padding(3, 2, 3, 2);
+            textBoxHeading.Name = "textBoxHeading";
+            textBoxHeading.Size = new Size(239, 23);
+            textBoxHeading.TabIndex = 20;
+            // 
+            // labelHeading
+            // 
+            labelHeading.AutoSize = true;
+            labelHeading.Location = new Point(81, 74);
+            labelHeading.Name = "labelHeading";
+            labelHeading.Size = new Size(65, 15);
+            labelHeading.TabIndex = 19;
+            labelHeading.Text = "Заголовок";
+            // 
+            // buttonUpdateAd
+            // 
+            buttonUpdateAd.Location = new Point(81, 425);
+            buttonUpdateAd.Margin = new Padding(3, 2, 3, 2);
+            buttonUpdateAd.Name = "buttonUpdateAd";
+            buttonUpdateAd.Size = new Size(239, 29);
+            buttonUpdateAd.TabIndex = 18;
+            buttonUpdateAd.Text = "Изменить объявление";
+            buttonUpdateAd.UseVisualStyleBackColor = true;
+            buttonUpdateAd.Click += buttonUpdateAd_Click;
+            // 
+            // label1
+            // 
+            label1.AutoSize = true;
+            label1.Location = new Point(51, 15);
+            label1.Name = "label1";
+            label1.Size = new Size(275, 15);
+            label1.TabIndex = 33;
+            label1.Text = "Выберите объявление, которое хотите обновить";
+            // 
+            // comboBoxUpdateAd
+            // 
+            comboBoxUpdateAd.FormattingEnabled = true;
+            comboBoxUpdateAd.Location = new Point(10, 39);
+            comboBoxUpdateAd.Margin = new Padding(3, 2, 3, 2);
+            comboBoxUpdateAd.Name = "comboBoxUpdateAd";
+            comboBoxUpdateAd.Size = new Size(377, 23);
+            comboBoxUpdateAd.TabIndex = 34;
+            comboBoxUpdateAd.SelectedIndexChanged += comboBoxUpdateAd_SelectedIndexChanged;
+            // 
+            // UpdateAdsForm
+            // 
+            AutoScaleDimensions = new SizeF(7F, 15F);
+            AutoScaleMode = AutoScaleMode.Font;
+            ClientSize = new Size(397, 473);
+            Controls.Add(comboBoxUpdateAd);
+            Controls.Add(label1);
+            Controls.Add(comboBoxClient);
+            Controls.Add(comboBoxCategory);
+            Controls.Add(comboBoxSubcategory);
+            Controls.Add(labelClient);
+            Controls.Add(labelSubcategory);
+            Controls.Add(labelCategory);
+            Controls.Add(textBoxStatus);
+            Controls.Add(labelStatus);
+            Controls.Add(textBoxDate);
+            Controls.Add(labelDate);
+            Controls.Add(textBoxPrice);
+            Controls.Add(labelPrice);
+            Controls.Add(textBoxHeading);
+            Controls.Add(labelHeading);
+            Controls.Add(buttonUpdateAd);
+            Margin = new Padding(3, 2, 3, 2);
+            Name = "UpdateAdsForm";
+            Text = "Обновить объявление";
+            ResumeLayout(false);
+            PerformLayout();
+        }
+
+        #endregion
+
+        private ComboBox comboBoxClient;
+        private ComboBox comboBoxCategory;
+        private ComboBox comboBoxSubcategory;
+        private Label labelClient;
+        private Label labelSubcategory;
+        private Label labelCategory;
+        private TextBox textBoxStatus;
+        private Label labelStatus;
+        private TextBox textBoxDate;
+        private Label labelDate;
+        private TextBox textBoxPrice;
+        private Label labelPrice;
+        private TextBox textBoxHeading;
+        private Label labelHeading;
+        private Button buttonUpdateAd;
+        private Label label1;
+        private ComboBox comboBoxUpdateAd;
+    }
+}

BulletinBoard/BulletinBoard/AdsForm/UpdateAdsForm.cs

@@ -0,0 +1,154 @@
+using System;
+using System.Collections.Generic;
+using System.ComponentModel;
+using System.Data;
+using System.Drawing;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using System.Windows.Forms;
+
+namespace WebsiteForPlacingAds
+{
+    public partial class UpdateAdsForm : Form
+    {
+        //PostgreSqlDatabase psd;
+        AbstractManagmentDatabase managmentDatabase;
+        public UpdateAdsForm(AbstractManagmentDatabase managmentDatabase)
+        {
+            InitializeComponent();
+            this.managmentDatabase = managmentDatabase;
+            LoadData();
+        }
+
+        private void buttonUpdateAd_Click(object sender, EventArgs e)
+        {
+            string[] selectedAds = comboBoxUpdateAd.SelectedItem.ToString().Split("|");
+            int ads_id = int.Parse(selectedAds[0].Trim());
+
+            string query = $"UPDATE ads SET ";
+            int len = query.Length;
+            
+
+            string oldHeading = managmentDatabase.getRowTableById("ads", "heading", ads_id).ToString();
+            string oldPrice = managmentDatabase.getRowTableById("ads", "heading", ads_id).ToString();
+            string oldDate = ((DateTime)managmentDatabase.getRowTableById("ads", "date_of_placement", ads_id)).ToString("dd.MM.yyyy");
+            string oldStatus = managmentDatabase.getRowTableById("ads", "status", ads_id).ToString();
+            string[] oldClient = managmentDatabase.getRowTableById("ads", "client_id", ads_id).ToString().Split(" ");
+            string[] oldCategory = managmentDatabase.getRowTableById("ads", "category_id", ads_id).ToString().Split(" ");
+            string[] oldSubcategory = managmentDatabase.getRowTableById("ads", "subcategory_id", ads_id).ToString().Split(" ");
+
+
+            string newHeading = textBoxHeading.Text;
+            string newPrice = textBoxPrice.Text;
+            string newDate = textBoxDate.Text;
+            string newStatus = textBoxStatus.Text;
+            string[] newClient = comboBoxClient.SelectedItem.ToString().Split(" ");
+            string[] newCategory = comboBoxCategory.SelectedItem.ToString().Split(" ");
+            string[] newSubcategory = comboBoxSubcategory.SelectedItem.ToString().Split(" ");
+
+
+
+            query = oldHeading == newHeading ? query : query + $"heading = '{newHeading}', ";
+            query = oldPrice == newPrice ? query : query + $"price = {newPrice}, ";
+            query = oldDate == newDate ? query : query + $"date_of_placement = '{newDate}', ";
+            query = oldStatus == newStatus ? query : query + $"status = '{newStatus}', ";
+            query = oldClient[0].Trim() == newClient[0].Trim() ? query : query + $"client_id = '{newClient[0].Substring(0, newClient[0].IndexOf("."))}', ";
+            query = oldCategory[0].Trim() == newCategory[0].Trim() ? query : query + $"category_id = '{newCategory[0].Substring(0, newCategory[0].IndexOf("."))}', ";
+            query = oldSubcategory[0].Trim() == newSubcategory[0].Trim() ? query : query + $"subcategory_id = '{newSubcategory[0].Substring(0, newSubcategory[0].IndexOf("."))}', ";
+
+
+            if (len != query.Length)
+            {
+                query = query.TrimEnd(' ');
+                query = query.TrimEnd(',');
+                query += $" WHERE ADS_ID = {ads_id};";
+            }
+            try
+            {
+                DateTime start = DateTime.Now;
+
+                managmentDatabase.ExecuteNonQuery(query);
+                MessageBox.Show("Данные успешно обновлены!");
+
+                DateTime end = DateTime.Now;
+                TimeSpan duration = end - start;
+                MessageBox.Show($"Добавлено! Время выполнения: {duration.TotalMilliseconds} мс");
+            }
+            catch (Exception)
+            {
+
+                MessageBox.Show("Данные не обновились");
+            }
+            
+        }
+        public void LoadData()
+        {
+            comboBoxUpdateAd.Items.Clear();
+            DataTable result = managmentDatabase.getAllEntry("Ads");
+            string Ads = "";
+            for (int i = 0; i < result.Rows.Count; i++)
+            {
+                Ads = result.Rows[i]["ads_id"].ToString() + " | " +
+                                (string)result.Rows[i]["heading"] + " | " +
+                                result.Rows[i]["price"].ToString() + " | " +
+                                ((DateTime)result.Rows[i]["date_of_placement"]).ToString("dd.MM.yyyy") + " | " +
+                                (string)result.Rows[i]["status"] + " | " +
+                                result.Rows[i]["client_id"].ToString() + " | " +
+                                result.Rows[i]["category_id"].ToString() + " | " +
+                                result.Rows[i]["subcategory_id"].ToString() + "\n";
+                comboBoxUpdateAd.Items.Add(Ads);
+            }
+            comboBoxCategory.Items.Clear();
+            comboBoxSubcategory.Items.Clear();
+            comboBoxClient.Items.Clear();
+
+            result = managmentDatabase.getAllEntry("Categories");
+            string[] id_names = new string[result.Rows.Count];
+            for (int i = 0; i < result.Rows.Count; i++)
+            {
+                id_names[i] = result.Rows[i]["categories_id"].ToString() + ". " + (string)result.Rows[i]["name"];
+                comboBoxCategory.Items.Add(id_names[i]);
+            }
+            result = managmentDatabase.getAllEntry("Subcategories");
+            id_names = new string[result.Rows.Count];
+            for (int i = 0; i < result.Rows.Count; i++)
+            {
+                id_names[i] = result.Rows[i]["subcategories_id"].ToString() + ". " + (string)result.Rows[i]["name"];
+                comboBoxSubcategory.Items.Add(id_names[i]);
+            }
+            result = managmentDatabase.getAllEntry("Clients");
+            string[] id_names_surnames = new string[result.Rows.Count];
+            for (int i = 0; i < result.Rows.Count; i++)
+            {
+                id_names_surnames[i] = result.Rows[i]["clients_id"].ToString().Trim() + ". " + ((string)result.Rows[i]["name"]).Trim() + " " + ((string)result.Rows[i]["surname"]).Trim();
+                comboBoxClient.Items.Add(id_names_surnames[i]);
+            }
+
+        }
+        public void LoadDataSelectedItem(int ads_id)
+        {
+            DataTable result = managmentDatabase.getEntryById("ads", ads_id);
+            textBoxHeading.Text = (string)result.Rows[0]["heading"];
+            textBoxPrice.Text = result.Rows[0]["price"].ToString();
+            textBoxDate.Text = ((DateTime)result.Rows[0]["date_of_placement"]).ToString("dd.MM.yyyy");
+            textBoxStatus.Text = (string)result.Rows[0]["status"];
+
+            comboBoxCategory.SelectedItem = result.Rows[0]["category_id"].ToString() + ". " + managmentDatabase.getRowTableById("categories", "name", Convert.ToInt32(result.Rows[0]["id_category"])).ToString();
+
+            comboBoxSubcategory.SelectedItem = result.Rows[0]["subcategory_id"].ToString() + ". " + managmentDatabase.getRowTableById("subcategories", "name", Convert.ToInt32(result.Rows[0]["id_subcategory"])).ToString();
+
+            comboBoxClient.SelectedItem = result.Rows[0]["id_client"].ToString().Trim() + ". " + 
+                managmentDatabase.getRowTableById("clients", "name", Convert.ToInt32(result.Rows[0]["client_id"])).ToString().Trim() + " " + 
+                managmentDatabase.getRowTableById("clients", "surname", Convert.ToInt32(result.Rows[0]["client_id"])).ToString().Trim();
+
+        }
+
+        private void comboBoxUpdateAd_SelectedIndexChanged(object sender, EventArgs e)
+        {
+            string[] selectedItems = comboBoxUpdateAd.SelectedItem.ToString().Split("|");
+            int ads_id = int.Parse(selectedItems[0].Trim());
+            LoadDataSelectedItem(ads_id);
+        }
+    }
+}

BulletinBoard/BulletinBoard/AdsForm/UpdateAdsForm.resx

@@ -0,0 +1,120 @@
+<?xml version="1.0" encoding="utf-8"?>
+<root>
+  <!--
+    Microsoft ResX Schema 
+
+    Version 2.0
+
+    The primary goals of this format is to allow a simple XML format
+    that is mostly human readable. The generation and parsing of the
+    various data types are done through the TypeConverter classes
+    associated with the data types.
+
+    Example:
+
+    ... ado.net/XML headers & schema ...
+    <resheader name="resmimetype">text/microsoft-resx</resheader>
+    <resheader name="version">2.0</resheader>
+    <resheader name="reader">System.Resources.ResXResourceReader, System.Windows.Forms, ...</resheader>
+    <resheader name="writer">System.Resources.ResXResourceWriter, System.Windows.Forms, ...</resheader>
+    <data name="Name1"><value>this is my long string</value><comment>this is a comment</comment></data>
+    <data name="Color1" type="System.Drawing.Color, System.Drawing">Blue</data>
+    <data name="Bitmap1" mimetype="application/x-microsoft.net.object.binary.base64">
+        <value>[base64 mime encoded serialized .NET Framework object]</value>
+    </data>
+    <data name="Icon1" type="System.Drawing.Icon, System.Drawing" mimetype="application/x-microsoft.net.object.bytearray.base64">
+        <value>[base64 mime encoded string representing a byte array form of the .NET Framework object]</value>
+        <comment>This is a comment</comment>
+    </data>
+
+    There are any number of "resheader" rows that contain simple
+    name/value pairs.
+
+    Each data row contains a name, and value. The row also contains a
+    type or mimetype. Type corresponds to a .NET class that support
+    text/value conversion through the TypeConverter architecture.
+    Classes that don't support this are serialized and stored with the
+    mimetype set.
+
+    The mimetype is used for serialized objects, and tells the
+    ResXResourceReader how to depersist the object. This is currently not
+    extensible. For a given mimetype the value must be set accordingly:
+
+    Note - application/x-microsoft.net.object.binary.base64 is the format
+    that the ResXResourceWriter will generate, however the reader can
+    read any of the formats listed below.
+
+    mimetype: application/x-microsoft.net.object.binary.base64
+    value   : The object must be serialized with
+            : System.Runtime.Serialization.Formatters.Binary.BinaryFormatter
+            : and then encoded with base64 encoding.
+    
+    mimetype: application/x-microsoft.net.object.soap.base64
+    value   : The object must be serialized with
+            : System.Runtime.Serialization.Formatters.Soap.SoapFormatter
+            : and then encoded with base64 encoding.
+
+    mimetype: application/x-microsoft.net.object.bytearray.base64
+    value   : The object must be serialized into a byte array
+            : using a System.ComponentModel.TypeConverter
+            : and then encoded with base64 encoding.
+    -->
+  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
+    <xsd:import namespace="http://www.w3.org/XML/1998/namespace" />
+    <xsd:element name="root" msdata:IsDataSet="true">
+      <xsd:complexType>
+        <xsd:choice maxOccurs="unbounded">
+          <xsd:element name="metadata">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" />
+              </xsd:sequence>
+              <xsd:attribute name="name" use="required" type="xsd:string" />
+              <xsd:attribute name="type" type="xsd:string" />
+              <xsd:attribute name="mimetype" type="xsd:string" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="assembly">
+            <xsd:complexType>
+              <xsd:attribute name="alias" type="xsd:string" />
+              <xsd:attribute name="name" type="xsd:string" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="data">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" msdata:Ordinal="1" />
+              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />
+              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="resheader">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" />
+            </xsd:complexType>
+          </xsd:element>
+        </xsd:choice>
+      </xsd:complexType>
+    </xsd:element>
+  </xsd:schema>
+  <resheader name="resmimetype">
+    <value>text/microsoft-resx</value>
+  </resheader>
+  <resheader name="version">
+    <value>2.0</value>
+  </resheader>
+  <resheader name="reader">
+    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+  <resheader name="writer">
+    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+</root>

BulletinBoard/BulletinBoard/BulletinBoard.csproj

@@ -0,0 +1,21 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>WinExe</OutputType>
+    <TargetFramework>net6.0-windows</TargetFramework>
+    <Nullable>enable</Nullable>
+    <UseWindowsForms>true</UseWindowsForms>
+    <ImplicitUsings>enable</ImplicitUsings>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Npgsql" Version="8.0.2" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <Compile Update="RegionsForm\CreateRegionsForm.cs">
+      <SubType>Form</SubType>
+    </Compile>
+  </ItemGroup>
+
+</Project>

BulletinBoard/BulletinBoard/CategoriesForm/CreateCategoriesForm.Designer.cs

@@ -0,0 +1,86 @@
+namespace WebsiteForPlacingAds
+{
+    partial class CreateCategoriesForm
+    {
+        /// <summary>
+        ///  Required designer variable.
+        /// </summary>
+        private System.ComponentModel.IContainer components = null;
+
+        /// <summary>
+        ///  Clean up any resources being used.
+        /// </summary>
+        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
+        protected override void Dispose(bool disposing)
+        {
+            if (disposing && (components != null))
+            {
+                components.Dispose();
+            }
+            base.Dispose(disposing);
+        }
+
+        #region Windows Form Designer generated code
+
+        /// <summary>
+        ///  Required method for Designer support - do not modify
+        ///  the contents of this method with the code editor.
+        /// </summary>
+        private void InitializeComponent()
+        {
+            this.buttonCreateCategory = new System.Windows.Forms.Button();
+            this.labelName = new System.Windows.Forms.Label();
+            this.textBoxName = new System.Windows.Forms.TextBox();
+            this.SuspendLayout();
+            // 
+            // buttonCreateCategory
+            // 
+            this.buttonCreateCategory.Location = new System.Drawing.Point(43, 70);
+            this.buttonCreateCategory.Margin = new System.Windows.Forms.Padding(3, 2, 3, 2);
+            this.buttonCreateCategory.Name = "buttonCreateCategory";
+            this.buttonCreateCategory.Size = new System.Drawing.Size(239, 29);
+            this.buttonCreateCategory.TabIndex = 0;
+            this.buttonCreateCategory.Text = "Добавить категорию";
+            this.buttonCreateCategory.UseVisualStyleBackColor = true;
+            this.buttonCreateCategory.Click += new System.EventHandler(this.buttonCreateCategory_Click);
+            // 
+            // labelName
+            // 
+            this.labelName.AutoSize = true;
+            this.labelName.Location = new System.Drawing.Point(43, 8);
+            this.labelName.Name = "labelName";
+            this.labelName.Size = new System.Drawing.Size(59, 15);
+            this.labelName.TabIndex = 1;
+            this.labelName.Text = "Название";
+            // 
+            // textBoxName
+            // 
+            this.textBoxName.Location = new System.Drawing.Point(43, 26);
+            this.textBoxName.Margin = new System.Windows.Forms.Padding(3, 2, 3, 2);
+            this.textBoxName.Name = "textBoxName";
+            this.textBoxName.Size = new System.Drawing.Size(239, 23);
+            this.textBoxName.TabIndex = 2;
+            // 
+            // CreateCategoriesForm
+            // 
+            this.AutoScaleDimensions = new System.Drawing.SizeF(7F, 15F);
+            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
+            this.ClientSize = new System.Drawing.Size(324, 127);
+            this.Controls.Add(this.textBoxName);
+            this.Controls.Add(this.labelName);
+            this.Controls.Add(this.buttonCreateCategory);
+            this.Margin = new System.Windows.Forms.Padding(3, 2, 3, 2);
+            this.Name = "CreateCategoriesForm";
+            this.Text = "Категория";
+            this.ResumeLayout(false);
+            this.PerformLayout();
+
+        }
+
+        #endregion
+
+        private Button buttonCreateCategory;
+        private Label labelName;
+        private TextBox textBoxName;
+    }
+}

BulletinBoard/BulletinBoard/CategoriesForm/CreateCategoriesForm.cs

@@ -0,0 +1,35 @@
+using System.Data;
+
+namespace WebsiteForPlacingAds
+{
+    public partial class CreateCategoriesForm : Form
+    {
+        AbstractManagmentDatabase managmentDatabase;
+        public CreateCategoriesForm(AbstractManagmentDatabase managmentDatabase)
+        {
+            InitializeComponent();
+            this.managmentDatabase = managmentDatabase;
+        }
+
+        private void buttonCreateCategory_Click(object sender, EventArgs e)
+        {
+            string name = textBoxName.Text;
+
+            try
+            {
+                DateTime start = DateTime.Now;
+
+                managmentDatabase.insertInto("categories", $"'{name}'");
+                MessageBox.Show("Äîáàâëåíî!");
+
+                DateTime end = DateTime.Now;
+                TimeSpan duration = end - start;
+                MessageBox.Show($"Äîáàâëåíî! Âðåìÿ âûïîëíåíèÿ: {duration.TotalMilliseconds} ìñ");
+            }
+            catch (Exception ex)
+            {
+                MessageBox.Show("Íå óäàëîñü äîáàâèòü");
+            }
+        }
+    }
+}

BulletinBoard/BulletinBoard/CategoriesForm/CreateCategoriesForm.resx

@@ -0,0 +1,60 @@
+<root>
+  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
+    <xsd:import namespace="http://www.w3.org/XML/1998/namespace" />
+    <xsd:element name="root" msdata:IsDataSet="true">
+      <xsd:complexType>
+        <xsd:choice maxOccurs="unbounded">
+          <xsd:element name="metadata">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" />
+              </xsd:sequence>
+              <xsd:attribute name="name" use="required" type="xsd:string" />
+              <xsd:attribute name="type" type="xsd:string" />
+              <xsd:attribute name="mimetype" type="xsd:string" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="assembly">
+            <xsd:complexType>
+              <xsd:attribute name="alias" type="xsd:string" />
+              <xsd:attribute name="name" type="xsd:string" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="data">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" msdata:Ordinal="1" />
+              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />
+              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="resheader">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" />
+            </xsd:complexType>
+          </xsd:element>
+        </xsd:choice>
+      </xsd:complexType>
+    </xsd:element>
+  </xsd:schema>
+  <resheader name="resmimetype">
+    <value>text/microsoft-resx</value>
+  </resheader>
+  <resheader name="version">
+    <value>2.0</value>
+  </resheader>
+  <resheader name="reader">
+    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+  <resheader name="writer">
+    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+</root>

BulletinBoard/BulletinBoard/CategoriesForm/DeleteCategoriesForm.Designer.cs

@@ -0,0 +1,87 @@
+namespace WebsiteForPlacingAds
+{
+    partial class DeleteCategoriesForm
+    {
+        /// <summary>
+        /// Required designer variable.
+        /// </summary>
+        private System.ComponentModel.IContainer components = null;
+
+        /// <summary>
+        /// Clean up any resources being used.
+        /// </summary>
+        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
+        protected override void Dispose(bool disposing)
+        {
+            if (disposing && (components != null))
+            {
+                components.Dispose();
+            }
+            base.Dispose(disposing);
+        }
+
+        #region Windows Form Designer generated code
+
+        /// <summary>
+        /// Required method for Designer support - do not modify
+        /// the contents of this method with the code editor.
+        /// </summary>
+        private void InitializeComponent()
+        {
+            this.label1 = new System.Windows.Forms.Label();
+            this.buttonDeleteCategory = new System.Windows.Forms.Button();
+            this.comboBoxDeleteCategories = new System.Windows.Forms.ComboBox();
+            this.SuspendLayout();
+            // 
+            // label1
+            // 
+            this.label1.AutoSize = true;
+            this.label1.Location = new System.Drawing.Point(70, 16);
+            this.label1.Name = "label1";
+            this.label1.Size = new System.Drawing.Size(262, 15);
+            this.label1.TabIndex = 0;
+            this.label1.Text = "Выберите категорию, которую хотите удалить";
+            // 
+            // buttonDeleteCategory
+            // 
+            this.buttonDeleteCategory.Location = new System.Drawing.Point(132, 85);
+            this.buttonDeleteCategory.Margin = new System.Windows.Forms.Padding(3, 2, 3, 2);
+            this.buttonDeleteCategory.Name = "buttonDeleteCategory";
+            this.buttonDeleteCategory.Size = new System.Drawing.Size(163, 28);
+            this.buttonDeleteCategory.TabIndex = 1;
+            this.buttonDeleteCategory.Text = "Удалить";
+            this.buttonDeleteCategory.UseVisualStyleBackColor = true;
+            this.buttonDeleteCategory.Click += new System.EventHandler(this.buttonDeleteCategory_Click);
+            // 
+            // comboBoxDeleteCategories
+            // 
+            this.comboBoxDeleteCategories.FormattingEnabled = true;
+            this.comboBoxDeleteCategories.Location = new System.Drawing.Point(35, 48);
+            this.comboBoxDeleteCategories.Margin = new System.Windows.Forms.Padding(3, 2, 3, 2);
+            this.comboBoxDeleteCategories.Name = "comboBoxDeleteCategories";
+            this.comboBoxDeleteCategories.Size = new System.Drawing.Size(367, 23);
+            this.comboBoxDeleteCategories.TabIndex = 2;
+            // 
+            // DeleteCategoriesForm
+            // 
+            this.AutoScaleDimensions = new System.Drawing.SizeF(7F, 15F);
+            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
+            this.ClientSize = new System.Drawing.Size(442, 131);
+            this.Controls.Add(this.comboBoxDeleteCategories);
+            this.Controls.Add(this.buttonDeleteCategory);
+            this.Controls.Add(this.label1);
+            this.Margin = new System.Windows.Forms.Padding(3, 2, 3, 2);
+            this.Name = "DeleteCategoriesForm";
+            this.Text = "Удалить категорию";
+            this.ResumeLayout(false);
+            this.PerformLayout();
+
+        }
+
+        #endregion
+
+        private Label label1;
+        private Button buttonDeleteCategory;
+        private ComboBox comboBoxDeleteCategories;
+    }
+}

BulletinBoard/BulletinBoard/CategoriesForm/DeleteCategoriesForm.cs

@@ -0,0 +1,61 @@
+using System;
+using System.Collections.Generic;
+using System.ComponentModel;
+using System.Data;
+using System.Drawing;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using System.Windows.Forms;
+
+namespace WebsiteForPlacingAds
+{
+    public partial class DeleteCategoriesForm : Form
+    {
+        AbstractManagmentDatabase managmentDatabase;
+        private int setval_seq;
+        public DeleteCategoriesForm(AbstractManagmentDatabase managmentDatabase)
+        {
+            InitializeComponent();
+            this.managmentDatabase = managmentDatabase;
+            LoadData();
+        }
+
+        private void buttonDeleteCategory_Click(object sender, EventArgs e)
+        {
+            string[] categories = comboBoxDeleteCategories.SelectedItem.ToString().Split("|");
+            string category_id = categories[0].Trim();
+            try
+            {
+                DateTime start = DateTime.Now;
+
+                managmentDatabase.deleteEntry("categories", int.Parse(category_id));
+                LoadData();
+                if (setval_seq > 0) managmentDatabase.reduceSeq("seq_categories", setval_seq);
+                MessageBox.Show("Удалено!");
+
+                DateTime end = DateTime.Now;
+                TimeSpan duration = end - start;
+                MessageBox.Show($"Добавлено! Время выполнения: {duration.TotalMilliseconds} мс");
+            }
+            catch (Exception ex)
+            {
+                MessageBox.Show("Не удалось удалить");
+            }
+        }
+        public void LoadData()
+        {
+            comboBoxDeleteCategories.Items.Clear();
+            DataTable result = managmentDatabase.getAllEntry("Categories");
+            setval_seq = result.Rows.Count;
+            string Categories = "";
+            for (int i = 0; i < result.Rows.Count; i++)
+            {
+                setval_seq = Math.Max(Convert.ToInt32(managmentDatabase.getRowTableById(result, "categories_id", i)), setval_seq);
+                Categories = managmentDatabase.getRowTableById(result, "categories_id", i).ToString() + " | " +
+                                managmentDatabase.getRowTableById(result, "name", i).ToString()  + "\n";
+                comboBoxDeleteCategories.Items.Add(Categories);
+            }
+        }
+    }
+}

BulletinBoard/BulletinBoard/CategoriesForm/DeleteCategoriesForm.resx

@@ -0,0 +1,60 @@
+<root>
+  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
+    <xsd:import namespace="http://www.w3.org/XML/1998/namespace" />
+    <xsd:element name="root" msdata:IsDataSet="true">
+      <xsd:complexType>
+        <xsd:choice maxOccurs="unbounded">
+          <xsd:element name="metadata">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" />
+              </xsd:sequence>
+              <xsd:attribute name="name" use="required" type="xsd:string" />
+              <xsd:attribute name="type" type="xsd:string" />
+              <xsd:attribute name="mimetype" type="xsd:string" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="assembly">
+            <xsd:complexType>
+              <xsd:attribute name="alias" type="xsd:string" />
+              <xsd:attribute name="name" type="xsd:string" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="data">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" msdata:Ordinal="1" />
+              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />
+              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="resheader">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" />
+            </xsd:complexType>
+          </xsd:element>
+        </xsd:choice>
+      </xsd:complexType>
+    </xsd:element>
+  </xsd:schema>
+  <resheader name="resmimetype">
+    <value>text/microsoft-resx</value>
+  </resheader>
+  <resheader name="version">
+    <value>2.0</value>
+  </resheader>
+  <resheader name="reader">
+    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+  <resheader name="writer">
+    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+</root>

BulletinBoard/BulletinBoard/CategoriesForm/ListCategoriesForm.Designer.cs

@@ -0,0 +1,75 @@
+namespace WebsiteForPlacingAds
+{
+    partial class ListCategoriesForm
+    {
+        /// <summary>
+        /// Required designer variable.
+        /// </summary>
+        private System.ComponentModel.IContainer components = null;
+
+        /// <summary>
+        /// Clean up any resources being used.
+        /// </summary>
+        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
+        protected override void Dispose(bool disposing)
+        {
+            if (disposing && (components != null))
+            {
+                components.Dispose();
+            }
+            base.Dispose(disposing);
+        }
+
+        #region Windows Form Designer generated code
+
+        /// <summary>
+        /// Required method for Designer support - do not modify
+        /// the contents of this method with the code editor.
+        /// </summary>
+        private void InitializeComponent()
+        {
+            this.label1 = new System.Windows.Forms.Label();
+            this.labelListCategories = new System.Windows.Forms.Label();
+            this.SuspendLayout();
+            // 
+            // label1
+            // 
+            this.label1.AutoSize = true;
+            this.label1.BackColor = System.Drawing.SystemColors.Control;
+            this.label1.Font = new System.Drawing.Font("Segoe UI", 11F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point);
+            this.label1.Location = new System.Drawing.Point(10, 7);
+            this.label1.Name = "label1";
+            this.label1.Size = new System.Drawing.Size(134, 20);
+            this.label1.TabIndex = 0;
+            this.label1.Text = "Список категорий";
+            // 
+            // labelListCategories
+            // 
+            this.labelListCategories.AutoSize = true;
+            this.labelListCategories.Font = new System.Drawing.Font("Segoe UI", 10F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point);
+            this.labelListCategories.Location = new System.Drawing.Point(10, 35);
+            this.labelListCategories.Name = "labelListCategories";
+            this.labelListCategories.Size = new System.Drawing.Size(0, 19);
+            this.labelListCategories.TabIndex = 1;
+            // 
+            // ListCategoriesForm
+            // 
+            this.AutoScaleDimensions = new System.Drawing.SizeF(7F, 15F);
+            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
+            this.ClientSize = new System.Drawing.Size(700, 338);
+            this.Controls.Add(this.labelListCategories);
+            this.Controls.Add(this.label1);
+            this.Margin = new System.Windows.Forms.Padding(3, 2, 3, 2);
+            this.Name = "ListCategoriesForm";
+            this.Text = "Список категорий";
+            this.ResumeLayout(false);
+            this.PerformLayout();
+
+        }
+
+        #endregion
+
+        private Label label1;
+        private Label labelListCategories;
+    }
+}

BulletinBoard/BulletinBoard/CategoriesForm/ListCategoriesForm.cs

@@ -0,0 +1,42 @@
+using System;
+using System.Collections.Generic;
+using System.ComponentModel;
+using System.Data;
+using System.Drawing;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using System.Windows.Forms;
+using System.Windows.Forms.VisualStyles;
+
+namespace WebsiteForPlacingAds
+{
+    public partial class ListCategoriesForm : Form
+    {
+        AbstractManagmentDatabase managmentDatabase;
+        public ListCategoriesForm(AbstractManagmentDatabase managmentDatabase)
+        {
+            InitializeComponent();
+            this.managmentDatabase = managmentDatabase;
+            LoadData();
+        }
+
+        private void LoadData()
+        {
+            DateTime start = DateTime.Now;
+
+            DataTable result = managmentDatabase.getAllEntry("Categories");
+            string listCategories = "";
+            for (int i = 0; i < result.Rows.Count; i++)
+            {
+                listCategories += managmentDatabase.getRowTableById(result, "categories_id", i).ToString() + " | " +
+                                managmentDatabase.getRowTableById(result, "name", i).ToString() + "\n";
+            }
+            labelListCategories.Text = listCategories;
+
+            DateTime end = DateTime.Now;
+            TimeSpan duration = end - start;
+            MessageBox.Show($"Список загружен! Время выполнения: {duration.TotalMilliseconds} мс");
+        }
+    }
+}

BulletinBoard/BulletinBoard/CategoriesForm/ListCategoriesForm.resx

@@ -0,0 +1,60 @@
+<root>
+  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
+    <xsd:import namespace="http://www.w3.org/XML/1998/namespace" />
+    <xsd:element name="root" msdata:IsDataSet="true">
+      <xsd:complexType>
+        <xsd:choice maxOccurs="unbounded">
+          <xsd:element name="metadata">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" />
+              </xsd:sequence>
+              <xsd:attribute name="name" use="required" type="xsd:string" />
+              <xsd:attribute name="type" type="xsd:string" />
+              <xsd:attribute name="mimetype" type="xsd:string" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="assembly">
+            <xsd:complexType>
+              <xsd:attribute name="alias" type="xsd:string" />
+              <xsd:attribute name="name" type="xsd:string" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="data">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" msdata:Ordinal="1" />
+              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />
+              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="resheader">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" />
+            </xsd:complexType>
+          </xsd:element>
+        </xsd:choice>
+      </xsd:complexType>
+    </xsd:element>
+  </xsd:schema>
+  <resheader name="resmimetype">
+    <value>text/microsoft-resx</value>
+  </resheader>
+  <resheader name="version">
+    <value>2.0</value>
+  </resheader>
+  <resheader name="reader">
+    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+  <resheader name="writer">
+    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+</root>

BulletinBoard/BulletinBoard/CategoriesForm/UpdateCategoriesForm.Designer.cs

@@ -0,0 +1,110 @@
+namespace WebsiteForPlacingAds
+{
+    partial class UpdateCategoriesForm
+    {
+        /// <summary>
+        /// Required designer variable.
+        /// </summary>
+        private System.ComponentModel.IContainer components = null;
+
+        /// <summary>
+        /// Clean up any resources being used.
+        /// </summary>
+        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
+        protected override void Dispose(bool disposing)
+        {
+            if (disposing && (components != null))
+            {
+                components.Dispose();
+            }
+            base.Dispose(disposing);
+        }
+
+        #region Windows Form Designer generated code
+
+        /// <summary>
+        /// Required method for Designer support - do not modify
+        /// the contents of this method with the code editor.
+        /// </summary>
+        private void InitializeComponent()
+        {
+            this.label1 = new System.Windows.Forms.Label();
+            this.comboBoxUpdateCategory = new System.Windows.Forms.ComboBox();
+            this.textBoxName = new System.Windows.Forms.TextBox();
+            this.labelName = new System.Windows.Forms.Label();
+            this.buttonUpdateCategory = new System.Windows.Forms.Button();
+            this.SuspendLayout();
+            // 
+            // label1
+            // 
+            this.label1.AutoSize = true;
+            this.label1.Location = new System.Drawing.Point(51, 15);
+            this.label1.Name = "label1";
+            this.label1.Size = new System.Drawing.Size(271, 15);
+            this.label1.TabIndex = 33;
+            this.label1.Text = "Выберите категорию, которую хотите обновить";
+            // 
+            // comboBoxUpdateCategory
+            // 
+            this.comboBoxUpdateCategory.FormattingEnabled = true;
+            this.comboBoxUpdateCategory.Location = new System.Drawing.Point(10, 39);
+            this.comboBoxUpdateCategory.Margin = new System.Windows.Forms.Padding(3, 2, 3, 2);
+            this.comboBoxUpdateCategory.Name = "comboBoxUpdateCategory";
+            this.comboBoxUpdateCategory.Size = new System.Drawing.Size(377, 23);
+            this.comboBoxUpdateCategory.TabIndex = 34;
+            this.comboBoxUpdateCategory.SelectedIndexChanged += new System.EventHandler(this.comboBoxUpdateCategory_SelectedIndexChanged);
+            // 
+            // textBoxName
+            // 
+            this.textBoxName.Location = new System.Drawing.Point(78, 96);
+            this.textBoxName.Margin = new System.Windows.Forms.Padding(3, 2, 3, 2);
+            this.textBoxName.Name = "textBoxName";
+            this.textBoxName.Size = new System.Drawing.Size(239, 23);
+            this.textBoxName.TabIndex = 37;
+            // 
+            // labelName
+            // 
+            this.labelName.AutoSize = true;
+            this.labelName.Location = new System.Drawing.Point(78, 78);
+            this.labelName.Name = "labelName";
+            this.labelName.Size = new System.Drawing.Size(59, 15);
+            this.labelName.TabIndex = 36;
+            this.labelName.Text = "Название";
+            // 
+            // buttonUpdateCategory
+            // 
+            this.buttonUpdateCategory.Location = new System.Drawing.Point(78, 140);
+            this.buttonUpdateCategory.Margin = new System.Windows.Forms.Padding(3, 2, 3, 2);
+            this.buttonUpdateCategory.Name = "buttonUpdateCategory";
+            this.buttonUpdateCategory.Size = new System.Drawing.Size(239, 29);
+            this.buttonUpdateCategory.TabIndex = 35;
+            this.buttonUpdateCategory.Text = "Обновить категорию";
+            this.buttonUpdateCategory.UseVisualStyleBackColor = true;
+            this.buttonUpdateCategory.Click += new System.EventHandler(this.buttonUpdateCategory_Click_1);
+            // 
+            // UpdateCategoriesForm
+            // 
+            this.AutoScaleDimensions = new System.Drawing.SizeF(7F, 15F);
+            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
+            this.ClientSize = new System.Drawing.Size(397, 190);
+            this.Controls.Add(this.textBoxName);
+            this.Controls.Add(this.labelName);
+            this.Controls.Add(this.buttonUpdateCategory);
+            this.Controls.Add(this.comboBoxUpdateCategory);
+            this.Controls.Add(this.label1);
+            this.Margin = new System.Windows.Forms.Padding(3, 2, 3, 2);
+            this.Name = "UpdateCategoriesForm";
+            this.Text = "Обновить категорию";
+            this.ResumeLayout(false);
+            this.PerformLayout();
+
+        }
+
+        #endregion
+        private Label label1;
+        private ComboBox comboBoxUpdateCategory;
+        private TextBox textBoxName;
+        private Label labelName;
+        private Button buttonUpdateCategory;
+    }
+}

BulletinBoard/BulletinBoard/CategoriesForm/UpdateCategoriesForm.cs

@@ -0,0 +1,86 @@
+using System;
+using System.Collections.Generic;
+using System.ComponentModel;
+using System.Data;
+using System.Drawing;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using System.Windows.Forms;
+
+namespace WebsiteForPlacingAds
+{
+    public partial class UpdateCategoriesForm : Form
+    {
+        AbstractManagmentDatabase managmentDatabase;
+        public UpdateCategoriesForm(AbstractManagmentDatabase managmentDatabase)
+        {
+            InitializeComponent();
+            this.managmentDatabase = managmentDatabase;
+            LoadData();
+        }
+        public void LoadData()
+        {
+            comboBoxUpdateCategory.Items.Clear();
+            DataTable result = managmentDatabase.getAllEntry("Categories");
+            string Categories = "";
+            for (int i = 0; i < result.Rows.Count; i++)
+            {
+                Categories = result.Rows[i]["categories_id"].ToString() + " | " +
+                                (string)result.Rows[i]["name"] + "\n";
+                comboBoxUpdateCategory.Items.Add(Categories);
+            }
+        }
+        public void LoadDataSelectedItem(int categories_id)
+        {
+            DataTable result = managmentDatabase.getEntryById("categories", categories_id);
+            textBoxName.Text = managmentDatabase.getRowTableById(result, "name", 0).ToString();
+        }
+
+        private void comboBoxUpdateCategory_SelectedIndexChanged(object sender, EventArgs e)
+        {
+            string[] selectedItems = comboBoxUpdateCategory.SelectedItem.ToString().Split("|");
+            int category_id = int.Parse(selectedItems[0].Trim());
+            LoadDataSelectedItem(category_id);
+        }
+
+        private void buttonUpdateCategory_Click_1(object sender, EventArgs e)
+        {
+            string[] selectedCategory = comboBoxUpdateCategory.SelectedItem.ToString().Split("|");
+            int category_id = int.Parse(selectedCategory[0].Trim());
+
+            string query = $"UPDATE Categories SET ";
+            int len = query.Length;
+
+
+            string oldName = managmentDatabase.getRowTableById("categories", "name", category_id).ToString();
+
+            string newName = textBoxName.Text;
+
+
+            query = oldName == newName ? query : query + $"name = '{newName}', ";
+            if (len != query.Length)
+            {
+                query = query.TrimEnd(' ');
+                query = query.TrimEnd(',');
+                query += $" WHERE Categories_ID = {category_id};";
+            }
+            try
+            {
+                DateTime start = DateTime.Now;
+
+                managmentDatabase.ExecuteNonQuery(query);
+                MessageBox.Show("Данные успешно обновлены!");
+
+                DateTime end = DateTime.Now;
+                TimeSpan duration = end - start;
+                MessageBox.Show($"Добавлено! Время выполнения: {duration.TotalMilliseconds} мс");
+            }
+            catch (Exception)
+            {
+
+                MessageBox.Show("Данные не обновились");
+            }
+        }
+    }
+}

BulletinBoard/BulletinBoard/CategoriesForm/UpdateCategoriesForm.resx

@@ -0,0 +1,60 @@
+<root>
+  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
+    <xsd:import namespace="http://www.w3.org/XML/1998/namespace" />
+    <xsd:element name="root" msdata:IsDataSet="true">
+      <xsd:complexType>
+        <xsd:choice maxOccurs="unbounded">
+          <xsd:element name="metadata">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" />
+              </xsd:sequence>
+              <xsd:attribute name="name" use="required" type="xsd:string" />
+              <xsd:attribute name="type" type="xsd:string" />
+              <xsd:attribute name="mimetype" type="xsd:string" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="assembly">
+            <xsd:complexType>
+              <xsd:attribute name="alias" type="xsd:string" />
+              <xsd:attribute name="name" type="xsd:string" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="data">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" msdata:Ordinal="1" />
+              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />
+              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="resheader">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" />
+            </xsd:complexType>
+          </xsd:element>
+        </xsd:choice>
+      </xsd:complexType>
+    </xsd:element>
+  </xsd:schema>
+  <resheader name="resmimetype">
+    <value>text/microsoft-resx</value>
+  </resheader>
+  <resheader name="version">
+    <value>2.0</value>
+  </resheader>
+  <resheader name="reader">
+    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+  <resheader name="writer">
+    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+</root>

BulletinBoard/BulletinBoard/CitiesForm/CreateCitiesForm.Designer.cs

@@ -0,0 +1,109 @@
+namespace WebsiteForPlacingAds
+{
+    partial class CreateCitiesForm
+    {
+        /// <summary>
+        ///  Required designer variable.
+        /// </summary>
+        private System.ComponentModel.IContainer components = null;
+
+        /// <summary>
+        ///  Clean up any resources being used.
+        /// </summary>
+        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
+        protected override void Dispose(bool disposing)
+        {
+            if (disposing && (components != null))
+            {
+                components.Dispose();
+            }
+            base.Dispose(disposing);
+        }
+
+        #region Windows Form Designer generated code
+
+        /// <summary>
+        ///  Required method for Designer support - do not modify
+        ///  the contents of this method with the code editor.
+        /// </summary>
+        private void InitializeComponent()
+        {
+            buttonCreateCity = new Button();
+            labelName = new Label();
+            textBoxName = new TextBox();
+            labelCategory = new Label();
+            comboBoxRegion = new ComboBox();
+            SuspendLayout();
+            // 
+            // buttonCreateCity
+            // 
+            buttonCreateCity.Location = new Point(43, 111);
+            buttonCreateCity.Margin = new Padding(3, 2, 3, 2);
+            buttonCreateCity.Name = "buttonCreateCity";
+            buttonCreateCity.Size = new Size(239, 29);
+            buttonCreateCity.TabIndex = 0;
+            buttonCreateCity.Text = "Добавить город";
+            buttonCreateCity.UseVisualStyleBackColor = true;
+            buttonCreateCity.Click += buttonCreateCity_Click;
+            // 
+            // labelName
+            // 
+            labelName.AutoSize = true;
+            labelName.Location = new Point(43, 8);
+            labelName.Name = "labelName";
+            labelName.Size = new Size(59, 15);
+            labelName.TabIndex = 1;
+            labelName.Text = "Название";
+            // 
+            // textBoxName
+            // 
+            textBoxName.Location = new Point(43, 26);
+            textBoxName.Margin = new Padding(3, 2, 3, 2);
+            textBoxName.Name = "textBoxName";
+            textBoxName.Size = new Size(239, 23);
+            textBoxName.TabIndex = 2;
+            // 
+            // labelCategory
+            // 
+            labelCategory.AutoSize = true;
+            labelCategory.Location = new Point(43, 62);
+            labelCategory.Name = "labelCategory";
+            labelCategory.Size = new Size(46, 15);
+            labelCategory.TabIndex = 20;
+            labelCategory.Text = "Регион";
+            // 
+            // comboBoxRegion
+            // 
+            comboBoxRegion.FormattingEnabled = true;
+            comboBoxRegion.Location = new Point(43, 78);
+            comboBoxRegion.Margin = new Padding(3, 2, 3, 2);
+            comboBoxRegion.Name = "comboBoxRegion";
+            comboBoxRegion.Size = new Size(239, 23);
+            comboBoxRegion.TabIndex = 19;
+            // 
+            // CreateCitiesForm
+            // 
+            AutoScaleDimensions = new SizeF(7F, 15F);
+            AutoScaleMode = AutoScaleMode.Font;
+            ClientSize = new Size(324, 163);
+            Controls.Add(labelCategory);
+            Controls.Add(comboBoxRegion);
+            Controls.Add(textBoxName);
+            Controls.Add(labelName);
+            Controls.Add(buttonCreateCity);
+            Margin = new Padding(3, 2, 3, 2);
+            Name = "CreateCitiesForm";
+            Text = "Добавить Город";
+            ResumeLayout(false);
+            PerformLayout();
+        }
+
+        #endregion
+
+        private Button buttonCreateCity;
+        private Label labelName;
+        private TextBox textBoxName;
+        private Label labelCategory;
+        private ComboBox comboBoxRegion;
+    }
+}

BulletinBoard/BulletinBoard/CitiesForm/CreateCitiesForm.cs

@@ -0,0 +1,56 @@
+using System.Data;
+
+namespace WebsiteForPlacingAds
+{
+    public partial class CreateCitiesForm : Form
+    {
+        AbstractManagmentDatabase managmentDatabase;
+        public CreateCitiesForm(AbstractManagmentDatabase managmentDatabase)
+        {
+            InitializeComponent();
+            this.managmentDatabase = managmentDatabase;
+            LoadData();
+        }
+
+        private void buttonCreateCity_Click(object sender, EventArgs e)
+        {
+            string name = textBoxName.Text;
+
+            string[] region = comboBoxRegion.SelectedItem.ToString().Split(" ");
+
+            string regions_id = region[0];
+
+            try
+            {
+                DateTime start = DateTime.Now;
+
+                managmentDatabase.insertInto("cities", $"'{name}'", regions_id);
+                MessageBox.Show("Äîáàâëåíî!");
+                LoadData();
+
+                DateTime end = DateTime.Now;
+                TimeSpan duration = end - start;
+                MessageBox.Show($"Äîáàâëåíî! Âðåìÿ âûïîëíåíèÿ: {duration.TotalMilliseconds} ìñ");
+
+                // Çàêðûòü òåêóùóþ ôîðìó ïîñëå âûïîëíåíèÿ äåéñòâèé
+                this.Close();
+            }
+            catch (Exception ex)
+            {
+                MessageBox.Show("Íå óäàëîñü äîáàâèòü");
+            }
+        }
+
+        private void LoadData()
+        {
+            comboBoxRegion.Items.Clear();
+            DataTable result = managmentDatabase.getAllEntry("REGIONS");
+            string[] id_names = new string[result.Rows.Count];
+            for (int i = 0; i < result.Rows.Count; i++)
+            {
+                id_names[i] = managmentDatabase.getRowTableById(result, "regions_id", i).ToString() + ". " + managmentDatabase.getRowTableById(result, "name", i).ToString();
+                comboBoxRegion.Items.Add(id_names[i]);
+            }
+        }
+    }
+}

BulletinBoard/BulletinBoard/CitiesForm/CreateCitiesForm.resx

@@ -0,0 +1,120 @@
+<?xml version="1.0" encoding="utf-8"?>
+<root>
+  <!--
+    Microsoft ResX Schema 
+
+    Version 2.0
+
+    The primary goals of this format is to allow a simple XML format
+    that is mostly human readable. The generation and parsing of the
+    various data types are done through the TypeConverter classes
+    associated with the data types.
+
+    Example:
+
+    ... ado.net/XML headers & schema ...
+    <resheader name="resmimetype">text/microsoft-resx</resheader>
+    <resheader name="version">2.0</resheader>
+    <resheader name="reader">System.Resources.ResXResourceReader, System.Windows.Forms, ...</resheader>
+    <resheader name="writer">System.Resources.ResXResourceWriter, System.Windows.Forms, ...</resheader>
+    <data name="Name1"><value>this is my long string</value><comment>this is a comment</comment></data>
+    <data name="Color1" type="System.Drawing.Color, System.Drawing">Blue</data>
+    <data name="Bitmap1" mimetype="application/x-microsoft.net.object.binary.base64">
+        <value>[base64 mime encoded serialized .NET Framework object]</value>
+    </data>
+    <data name="Icon1" type="System.Drawing.Icon, System.Drawing" mimetype="application/x-microsoft.net.object.bytearray.base64">
+        <value>[base64 mime encoded string representing a byte array form of the .NET Framework object]</value>
+        <comment>This is a comment</comment>
+    </data>
+
+    There are any number of "resheader" rows that contain simple
+    name/value pairs.
+
+    Each data row contains a name, and value. The row also contains a
+    type or mimetype. Type corresponds to a .NET class that support
+    text/value conversion through the TypeConverter architecture.
+    Classes that don't support this are serialized and stored with the
+    mimetype set.
+
+    The mimetype is used for serialized objects, and tells the
+    ResXResourceReader how to depersist the object. This is currently not
+    extensible. For a given mimetype the value must be set accordingly:
+
+    Note - application/x-microsoft.net.object.binary.base64 is the format
+    that the ResXResourceWriter will generate, however the reader can
+    read any of the formats listed below.
+
+    mimetype: application/x-microsoft.net.object.binary.base64
+    value   : The object must be serialized with
+            : System.Runtime.Serialization.Formatters.Binary.BinaryFormatter
+            : and then encoded with base64 encoding.
+    
+    mimetype: application/x-microsoft.net.object.soap.base64
+    value   : The object must be serialized with
+            : System.Runtime.Serialization.Formatters.Soap.SoapFormatter
+            : and then encoded with base64 encoding.
+
+    mimetype: application/x-microsoft.net.object.bytearray.base64
+    value   : The object must be serialized into a byte array
+            : using a System.ComponentModel.TypeConverter
+            : and then encoded with base64 encoding.
+    -->
+  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
+    <xsd:import namespace="http://www.w3.org/XML/1998/namespace" />
+    <xsd:element name="root" msdata:IsDataSet="true">
+      <xsd:complexType>
+        <xsd:choice maxOccurs="unbounded">
+          <xsd:element name="metadata">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" />
+              </xsd:sequence>
+              <xsd:attribute name="name" use="required" type="xsd:string" />
+              <xsd:attribute name="type" type="xsd:string" />
+              <xsd:attribute name="mimetype" type="xsd:string" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="assembly">
+            <xsd:complexType>
+              <xsd:attribute name="alias" type="xsd:string" />
+              <xsd:attribute name="name" type="xsd:string" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="data">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" msdata:Ordinal="1" />
+              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />
+              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="resheader">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" />
+            </xsd:complexType>
+          </xsd:element>
+        </xsd:choice>
+      </xsd:complexType>
+    </xsd:element>
+  </xsd:schema>
+  <resheader name="resmimetype">
+    <value>text/microsoft-resx</value>
+  </resheader>
+  <resheader name="version">
+    <value>2.0</value>
+  </resheader>
+  <resheader name="reader">
+    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+  <resheader name="writer">
+    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+</root>

BulletinBoard/BulletinBoard/CitiesForm/DeleteCitiesForm.Designer.cs

@@ -0,0 +1,86 @@
+namespace WebsiteForPlacingAds
+{
+    partial class DeleteCitiesForm
+    {
+        /// <summary>
+        /// Required designer variable.
+        /// </summary>
+        private System.ComponentModel.IContainer components = null;
+
+        /// <summary>
+        /// Clean up any resources being used.
+        /// </summary>
+        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
+        protected override void Dispose(bool disposing)
+        {
+            if (disposing && (components != null))
+            {
+                components.Dispose();
+            }
+            base.Dispose(disposing);
+        }
+
+        #region Windows Form Designer generated code
+
+        /// <summary>
+        /// Required method for Designer support - do not modify
+        /// the contents of this method with the code editor.
+        /// </summary>
+        private void InitializeComponent()
+        {
+            label1 = new Label();
+            buttonDeleteCity = new Button();
+            comboBoxDeleteCities = new ComboBox();
+            SuspendLayout();
+            // 
+            // label1
+            // 
+            label1.AutoSize = true;
+            label1.Location = new Point(70, 16);
+            label1.Name = "label1";
+            label1.Size = new Size(235, 15);
+            label1.TabIndex = 0;
+            label1.Text = "Выберите город, которую хотите удалить";
+            // 
+            // buttonDeleteCity
+            // 
+            buttonDeleteCity.Location = new Point(132, 85);
+            buttonDeleteCity.Margin = new Padding(3, 2, 3, 2);
+            buttonDeleteCity.Name = "buttonDeleteCity";
+            buttonDeleteCity.Size = new Size(163, 28);
+            buttonDeleteCity.TabIndex = 1;
+            buttonDeleteCity.Text = "Удалить";
+            buttonDeleteCity.UseVisualStyleBackColor = true;
+            buttonDeleteCity.Click += buttonDeleteCity_Click;
+            // 
+            // comboBoxDeleteCities
+            // 
+            comboBoxDeleteCities.FormattingEnabled = true;
+            comboBoxDeleteCities.Location = new Point(35, 48);
+            comboBoxDeleteCities.Margin = new Padding(3, 2, 3, 2);
+            comboBoxDeleteCities.Name = "comboBoxDeleteCities";
+            comboBoxDeleteCities.Size = new Size(367, 23);
+            comboBoxDeleteCities.TabIndex = 2;
+            // 
+            // DeleteCitiesForm
+            // 
+            AutoScaleDimensions = new SizeF(7F, 15F);
+            AutoScaleMode = AutoScaleMode.Font;
+            ClientSize = new Size(442, 131);
+            Controls.Add(comboBoxDeleteCities);
+            Controls.Add(buttonDeleteCity);
+            Controls.Add(label1);
+            Margin = new Padding(3, 2, 3, 2);
+            Name = "DeleteCitiesForm";
+            Text = "Удалить город";
+            ResumeLayout(false);
+            PerformLayout();
+        }
+
+        #endregion
+
+        private Label label1;
+        private Button buttonDeleteCity;
+        private ComboBox comboBoxDeleteCities;
+    }
+}

BulletinBoard/BulletinBoard/CitiesForm/DeleteCitiesForm.cs

@@ -0,0 +1,61 @@
+using System;
+using System.Collections.Generic;
+using System.ComponentModel;
+using System.Data;
+using System.Drawing;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using System.Windows.Forms;
+
+namespace WebsiteForPlacingAds
+{
+    public partial class DeleteCitiesForm : Form
+    {
+        AbstractManagmentDatabase managmentDatabase;
+        private int setval_seq;
+        public DeleteCitiesForm(AbstractManagmentDatabase managmentDatabase)
+        {
+            InitializeComponent();
+            this.managmentDatabase = managmentDatabase;
+            LoadData();
+        }
+
+        private void buttonDeleteCity_Click(object sender, EventArgs e)
+        {
+            string[] categories = comboBoxDeleteCities.SelectedItem.ToString().Split("|");
+            string category_id = categories[0].Trim();
+            try
+            {
+                DateTime start = DateTime.Now;
+
+                managmentDatabase.deleteEntry("cities", int.Parse(category_id));
+                LoadData();
+                if (setval_seq > 0) managmentDatabase.reduceSeq("seq_cities", setval_seq);
+                MessageBox.Show("Удалено!");
+
+                DateTime end = DateTime.Now;
+                TimeSpan duration = end - start;
+                MessageBox.Show($"Добавлено! Время выполнения: {duration.TotalMilliseconds} мс");
+            }
+            catch (Exception ex)
+            {
+                MessageBox.Show("Не удалось удалить");
+            }
+        }
+        public void LoadData()
+        {
+            comboBoxDeleteCities.Items.Clear();
+            DataTable result = managmentDatabase.getAllEntry("Cities");
+            setval_seq = result.Rows.Count;
+            string Regions = "";
+            for (int i = 0; i < result.Rows.Count; i++)
+            {
+                setval_seq = Math.Max(Convert.ToInt32(managmentDatabase.getRowTableById(result, "cities_id", i)), setval_seq);
+                Regions = managmentDatabase.getRowTableById(result, "cities_id", i).ToString() + " | " +
+                                managmentDatabase.getRowTableById(result, "name", i).ToString()  + "\n";
+                comboBoxDeleteCities.Items.Add(Regions);
+            }
+        }
+    }
+}

BulletinBoard/BulletinBoard/CitiesForm/DeleteCitiesForm.resx

@@ -0,0 +1,120 @@
+<?xml version="1.0" encoding="utf-8"?>
+<root>
+  <!--
+    Microsoft ResX Schema 
+
+    Version 2.0
+
+    The primary goals of this format is to allow a simple XML format
+    that is mostly human readable. The generation and parsing of the
+    various data types are done through the TypeConverter classes
+    associated with the data types.
+
+    Example:
+
+    ... ado.net/XML headers & schema ...
+    <resheader name="resmimetype">text/microsoft-resx</resheader>
+    <resheader name="version">2.0</resheader>
+    <resheader name="reader">System.Resources.ResXResourceReader, System.Windows.Forms, ...</resheader>
+    <resheader name="writer">System.Resources.ResXResourceWriter, System.Windows.Forms, ...</resheader>
+    <data name="Name1"><value>this is my long string</value><comment>this is a comment</comment></data>
+    <data name="Color1" type="System.Drawing.Color, System.Drawing">Blue</data>
+    <data name="Bitmap1" mimetype="application/x-microsoft.net.object.binary.base64">
+        <value>[base64 mime encoded serialized .NET Framework object]</value>
+    </data>
+    <data name="Icon1" type="System.Drawing.Icon, System.Drawing" mimetype="application/x-microsoft.net.object.bytearray.base64">
+        <value>[base64 mime encoded string representing a byte array form of the .NET Framework object]</value>
+        <comment>This is a comment</comment>
+    </data>
+
+    There are any number of "resheader" rows that contain simple
+    name/value pairs.
+
+    Each data row contains a name, and value. The row also contains a
+    type or mimetype. Type corresponds to a .NET class that support
+    text/value conversion through the TypeConverter architecture.
+    Classes that don't support this are serialized and stored with the
+    mimetype set.
+
+    The mimetype is used for serialized objects, and tells the
+    ResXResourceReader how to depersist the object. This is currently not
+    extensible. For a given mimetype the value must be set accordingly:
+
+    Note - application/x-microsoft.net.object.binary.base64 is the format
+    that the ResXResourceWriter will generate, however the reader can
+    read any of the formats listed below.
+
+    mimetype: application/x-microsoft.net.object.binary.base64
+    value   : The object must be serialized with
+            : System.Runtime.Serialization.Formatters.Binary.BinaryFormatter
+            : and then encoded with base64 encoding.
+    
+    mimetype: application/x-microsoft.net.object.soap.base64
+    value   : The object must be serialized with
+            : System.Runtime.Serialization.Formatters.Soap.SoapFormatter
+            : and then encoded with base64 encoding.
+
+    mimetype: application/x-microsoft.net.object.bytearray.base64
+    value   : The object must be serialized into a byte array
+            : using a System.ComponentModel.TypeConverter
+            : and then encoded with base64 encoding.
+    -->
+  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
+    <xsd:import namespace="http://www.w3.org/XML/1998/namespace" />
+    <xsd:element name="root" msdata:IsDataSet="true">
+      <xsd:complexType>
+        <xsd:choice maxOccurs="unbounded">
+          <xsd:element name="metadata">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" />
+              </xsd:sequence>
+              <xsd:attribute name="name" use="required" type="xsd:string" />
+              <xsd:attribute name="type" type="xsd:string" />
+              <xsd:attribute name="mimetype" type="xsd:string" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="assembly">
+            <xsd:complexType>
+              <xsd:attribute name="alias" type="xsd:string" />
+              <xsd:attribute name="name" type="xsd:string" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="data">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" msdata:Ordinal="1" />
+              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />
+              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="resheader">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" />
+            </xsd:complexType>
+          </xsd:element>
+        </xsd:choice>
+      </xsd:complexType>
+    </xsd:element>
+  </xsd:schema>
+  <resheader name="resmimetype">
+    <value>text/microsoft-resx</value>
+  </resheader>
+  <resheader name="version">
+    <value>2.0</value>
+  </resheader>
+  <resheader name="reader">
+    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+  <resheader name="writer">
+    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+</root>

BulletinBoard/BulletinBoard/CitiesForm/ListCitiesForm.Designer.cs

@@ -0,0 +1,74 @@
+namespace WebsiteForPlacingAds
+{
+    partial class ListCitiesForm
+    {
+        /// <summary>
+        /// Required designer variable.
+        /// </summary>
+        private System.ComponentModel.IContainer components = null;
+
+        /// <summary>
+        /// Clean up any resources being used.
+        /// </summary>
+        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
+        protected override void Dispose(bool disposing)
+        {
+            if (disposing && (components != null))
+            {
+                components.Dispose();
+            }
+            base.Dispose(disposing);
+        }
+
+        #region Windows Form Designer generated code
+
+        /// <summary>
+        /// Required method for Designer support - do not modify
+        /// the contents of this method with the code editor.
+        /// </summary>
+        private void InitializeComponent()
+        {
+            label1 = new Label();
+            labelListCities = new Label();
+            SuspendLayout();
+            // 
+            // label1
+            // 
+            label1.AutoSize = true;
+            label1.BackColor = SystemColors.Control;
+            label1.Font = new Font("Segoe UI", 11F, FontStyle.Regular, GraphicsUnit.Point);
+            label1.Location = new Point(10, 7);
+            label1.Name = "label1";
+            label1.Size = new Size(121, 20);
+            label1.TabIndex = 0;
+            label1.Text = "Список городов";
+            // 
+            // labelListCities
+            // 
+            labelListCities.AutoSize = true;
+            labelListCities.Font = new Font("Segoe UI", 10F, FontStyle.Regular, GraphicsUnit.Point);
+            labelListCities.Location = new Point(10, 35);
+            labelListCities.Name = "labelListCities";
+            labelListCities.Size = new Size(0, 19);
+            labelListCities.TabIndex = 1;
+            // 
+            // ListCitiesForm
+            // 
+            AutoScaleDimensions = new SizeF(7F, 15F);
+            AutoScaleMode = AutoScaleMode.Font;
+            ClientSize = new Size(700, 338);
+            Controls.Add(labelListCities);
+            Controls.Add(label1);
+            Margin = new Padding(3, 2, 3, 2);
+            Name = "ListCitiesForm";
+            Text = "Список городов";
+            ResumeLayout(false);
+            PerformLayout();
+        }
+
+        #endregion
+
+        private Label label1;
+        private Label labelListCities;
+    }
+}

BulletinBoard/BulletinBoard/CitiesForm/ListCitiesForm.cs

@@ -0,0 +1,42 @@
+using System;
+using System.Collections.Generic;
+using System.ComponentModel;
+using System.Data;
+using System.Drawing;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using System.Windows.Forms;
+using System.Windows.Forms.VisualStyles;
+
+namespace WebsiteForPlacingAds
+{
+    public partial class ListCitiesForm : Form
+    {
+        AbstractManagmentDatabase managmentDatabase;
+        public ListCitiesForm(AbstractManagmentDatabase managmentDatabase)
+        {
+            InitializeComponent();
+            this.managmentDatabase = managmentDatabase;
+            LoadData();
+        }
+
+        private void LoadData()
+        {
+            DateTime start = DateTime.Now;
+
+            DataTable result = managmentDatabase.getAllEntry("Cities");
+            string listCities = "";
+            for (int i = 0; i < result.Rows.Count; i++)
+            {
+                listCities += managmentDatabase.getRowTableById(result, "cities_id", i).ToString() + " | " +
+                                managmentDatabase.getRowTableById(result, "name", i).ToString() + "\n";
+            }
+            labelListCities.Text = listCities;
+
+            DateTime end = DateTime.Now;
+            TimeSpan duration = end - start;
+            MessageBox.Show($"Добавлено! Время выполнения: {duration.TotalMilliseconds} мс");
+        }
+    }
+}

BulletinBoard/BulletinBoard/CitiesForm/ListCitiesForm.resx

@@ -0,0 +1,120 @@
+<?xml version="1.0" encoding="utf-8"?>
+<root>
+  <!--
+    Microsoft ResX Schema 
+
+    Version 2.0
+
+    The primary goals of this format is to allow a simple XML format
+    that is mostly human readable. The generation and parsing of the
+    various data types are done through the TypeConverter classes
+    associated with the data types.
+
+    Example:
+
+    ... ado.net/XML headers & schema ...
+    <resheader name="resmimetype">text/microsoft-resx</resheader>
+    <resheader name="version">2.0</resheader>
+    <resheader name="reader">System.Resources.ResXResourceReader, System.Windows.Forms, ...</resheader>
+    <resheader name="writer">System.Resources.ResXResourceWriter, System.Windows.Forms, ...</resheader>
+    <data name="Name1"><value>this is my long string</value><comment>this is a comment</comment></data>
+    <data name="Color1" type="System.Drawing.Color, System.Drawing">Blue</data>
+    <data name="Bitmap1" mimetype="application/x-microsoft.net.object.binary.base64">
+        <value>[base64 mime encoded serialized .NET Framework object]</value>
+    </data>
+    <data name="Icon1" type="System.Drawing.Icon, System.Drawing" mimetype="application/x-microsoft.net.object.bytearray.base64">
+        <value>[base64 mime encoded string representing a byte array form of the .NET Framework object]</value>
+        <comment>This is a comment</comment>
+    </data>
+
+    There are any number of "resheader" rows that contain simple
+    name/value pairs.
+
+    Each data row contains a name, and value. The row also contains a
+    type or mimetype. Type corresponds to a .NET class that support
+    text/value conversion through the TypeConverter architecture.
+    Classes that don't support this are serialized and stored with the
+    mimetype set.
+
+    The mimetype is used for serialized objects, and tells the
+    ResXResourceReader how to depersist the object. This is currently not
+    extensible. For a given mimetype the value must be set accordingly:
+
+    Note - application/x-microsoft.net.object.binary.base64 is the format
+    that the ResXResourceWriter will generate, however the reader can
+    read any of the formats listed below.
+
+    mimetype: application/x-microsoft.net.object.binary.base64
+    value   : The object must be serialized with
+            : System.Runtime.Serialization.Formatters.Binary.BinaryFormatter
+            : and then encoded with base64 encoding.
+    
+    mimetype: application/x-microsoft.net.object.soap.base64
+    value   : The object must be serialized with
+            : System.Runtime.Serialization.Formatters.Soap.SoapFormatter
+            : and then encoded with base64 encoding.
+
+    mimetype: application/x-microsoft.net.object.bytearray.base64
+    value   : The object must be serialized into a byte array
+            : using a System.ComponentModel.TypeConverter
+            : and then encoded with base64 encoding.
+    -->
+  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
+    <xsd:import namespace="http://www.w3.org/XML/1998/namespace" />
+    <xsd:element name="root" msdata:IsDataSet="true">
+      <xsd:complexType>
+        <xsd:choice maxOccurs="unbounded">
+          <xsd:element name="metadata">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" />
+              </xsd:sequence>
+              <xsd:attribute name="name" use="required" type="xsd:string" />
+              <xsd:attribute name="type" type="xsd:string" />
+              <xsd:attribute name="mimetype" type="xsd:string" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="assembly">
+            <xsd:complexType>
+              <xsd:attribute name="alias" type="xsd:string" />
+              <xsd:attribute name="name" type="xsd:string" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="data">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" msdata:Ordinal="1" />
+              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />
+              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="resheader">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" />
+            </xsd:complexType>
+          </xsd:element>
+        </xsd:choice>
+      </xsd:complexType>
+    </xsd:element>
+  </xsd:schema>
+  <resheader name="resmimetype">
+    <value>text/microsoft-resx</value>
+  </resheader>
+  <resheader name="version">
+    <value>2.0</value>
+  </resheader>
+  <resheader name="reader">
+    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+  <resheader name="writer">
+    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+</root>

BulletinBoard/BulletinBoard/CitiesForm/UpdateCitiesForm.Designer.cs

@@ -0,0 +1,111 @@
+namespace WebsiteForPlacingAds
+{
+    partial class UpdateCitiesForm
+    {
+        /// <summary>
+        /// Required designer variable.
+        /// </summary>
+        private System.ComponentModel.IContainer components = null;
+
+        /// <summary>
+        /// Clean up any resources being used.
+        /// </summary>
+        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
+        protected override void Dispose(bool disposing)
+        {
+            if (disposing && (components != null))
+            {
+                components.Dispose();
+            }
+            base.Dispose(disposing);
+        }
+
+        #region Windows Form Designer generated code
+
+        /// <summary>
+        /// Required method for Designer support - do not modify
+        /// the contents of this method with the code editor.
+        /// </summary>
+        private void InitializeComponent()
+        {
+            label1 = new Label();
+            comboBoxUpdateCity = new ComboBox();
+            textBoxName = new TextBox();
+            labelName = new Label();
+            buttonUpdateCity = new Button();
+            SuspendLayout();
+            // 
+            // label1
+            // 
+            label1.AutoSize = true;
+            label1.Location = new Point(51, 15);
+            label1.Name = "label1";
+            label1.Size = new Size(244, 15);
+            label1.TabIndex = 33;
+            label1.Text = "Выберите город, который хотите обновить";
+            // 
+            // comboBoxUpdateCity
+            // 
+            comboBoxUpdateCity.FormattingEnabled = true;
+            comboBoxUpdateCity.Location = new Point(10, 39);
+            comboBoxUpdateCity.Margin = new Padding(3, 2, 3, 2);
+            comboBoxUpdateCity.Name = "comboBoxUpdateCity";
+            comboBoxUpdateCity.Size = new Size(377, 23);
+            comboBoxUpdateCity.TabIndex = 34;
+            comboBoxUpdateCity.SelectedIndexChanged += comboBoxUpdateCity_SelectedIndexChanged;
+            // 
+            // textBoxName
+            // 
+            textBoxName.Location = new Point(78, 96);
+            textBoxName.Margin = new Padding(3, 2, 3, 2);
+            textBoxName.Name = "textBoxName";
+            textBoxName.Size = new Size(239, 23);
+            textBoxName.TabIndex = 37;
+            // 
+            // labelName
+            // 
+            labelName.AutoSize = true;
+            labelName.Location = new Point(78, 78);
+            labelName.Name = "labelName";
+            labelName.Size = new Size(59, 15);
+            labelName.TabIndex = 36;
+            labelName.Text = "Название";
+            // 
+            // buttonUpdateCity
+            // 
+            buttonUpdateCity.Location = new Point(78, 140);
+            buttonUpdateCity.Margin = new Padding(3, 2, 3, 2);
+            buttonUpdateCity.Name = "buttonUpdateCity";
+            buttonUpdateCity.Size = new Size(239, 29);
+            buttonUpdateCity.TabIndex = 35;
+            buttonUpdateCity.Text = "Обновить город";
+            buttonUpdateCity.UseVisualStyleBackColor = true;
+            buttonUpdateCity.Click += buttonUpdateCity_Click_1;
+            // 
+            // UpdateCitiesForm
+            // 
+            AutoScaleDimensions = new SizeF(7F, 15F);
+            AutoScaleMode = AutoScaleMode.Font;
+            ClientSize = new Size(397, 190);
+            Controls.Add(textBoxName);
+            Controls.Add(labelName);
+            Controls.Add(buttonUpdateCity);
+            Controls.Add(comboBoxUpdateCity);
+            Controls.Add(label1);
+            Margin = new Padding(3, 2, 3, 2);
+            Name = "UpdateCitiesForm";
+            Text = "Обновить город";
+            ResumeLayout(false);
+            PerformLayout();
+        }
+
+        #endregion
+
+
+        private Label label1;
+        private ComboBox comboBoxUpdateCity;
+        private TextBox textBoxName;
+        private Label labelName;
+        private Button buttonUpdateCity;
+    }
+}

BulletinBoard/BulletinBoard/CitiesForm/UpdateCitiesForm.cs

@@ -0,0 +1,86 @@
+using System;
+using System.Collections.Generic;
+using System.ComponentModel;
+using System.Data;
+using System.Drawing;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using System.Windows.Forms;
+
+namespace WebsiteForPlacingAds
+{
+    public partial class UpdateCitiesForm : Form
+    {
+        AbstractManagmentDatabase managmentDatabase;
+        public UpdateCitiesForm(AbstractManagmentDatabase managmentDatabase)
+        {
+            InitializeComponent();
+            this.managmentDatabase = managmentDatabase;
+            LoadData();
+        }
+        public void LoadData()
+        {
+            DateTime start = DateTime.Now;
+
+            comboBoxUpdateCity.Items.Clear();
+            DataTable result = managmentDatabase.getAllEntry("Cities");
+            string Cities = "";
+            for (int i = 0; i < result.Rows.Count; i++)
+            {
+                Cities = result.Rows[i]["cities_id"].ToString() + " | " +
+                                (string)result.Rows[i]["name"] + "\n";
+                comboBoxUpdateCity.Items.Add(Cities);
+            }
+
+            DateTime end = DateTime.Now;
+            TimeSpan duration = end - start;
+            MessageBox.Show($"Добавлено! Время выполнения: {duration.TotalMilliseconds} мс");
+        }
+        public void LoadDataSelectedItem(int cities_id)
+        {
+            DataTable result = managmentDatabase.getEntryById("regions", cities_id);
+            textBoxName.Text = managmentDatabase.getRowTableById(result, "name", 0).ToString();
+        }
+
+        private void comboBoxUpdateCity_SelectedIndexChanged(object sender, EventArgs e)
+        {
+            string[] selectedItems = comboBoxUpdateCity.SelectedItem.ToString().Split("|");
+            int city_id = int.Parse(selectedItems[0].Trim());
+            LoadDataSelectedItem(city_id);
+        }
+
+        private void buttonUpdateCity_Click_1(object sender, EventArgs e)
+        {
+            string[] selectedCategory = comboBoxUpdateCity.SelectedItem.ToString().Split("|");
+            int city_id = int.Parse(selectedCategory[0].Trim());
+
+            string query = $"UPDATE Cities SET ";
+            int len = query.Length;
+
+
+            string oldName = managmentDatabase.getRowTableById("cities", "name", city_id).ToString();
+
+            string newName = textBoxName.Text;
+
+
+            query = oldName == newName ? query : query + $"name = '{newName}', ";
+            if (len != query.Length)
+            {
+                query = query.TrimEnd(' ');
+                query = query.TrimEnd(',');
+                query += $" WHERE Cities_ID = {city_id};";
+            }
+            try
+            {
+                managmentDatabase.ExecuteNonQuery(query);
+                MessageBox.Show("Данные успешно обновлены!");
+            }
+            catch (Exception)
+            {
+
+                MessageBox.Show("Данные не обновились");
+            }
+        }
+    }
+}

BulletinBoard/BulletinBoard/CitiesForm/UpdateCitiesForm.resx

@@ -0,0 +1,120 @@
+<?xml version="1.0" encoding="utf-8"?>
+<root>
+  <!--
+    Microsoft ResX Schema 
+
+    Version 2.0
+
+    The primary goals of this format is to allow a simple XML format
+    that is mostly human readable. The generation and parsing of the
+    various data types are done through the TypeConverter classes
+    associated with the data types.
+
+    Example:
+
+    ... ado.net/XML headers & schema ...
+    <resheader name="resmimetype">text/microsoft-resx</resheader>
+    <resheader name="version">2.0</resheader>
+    <resheader name="reader">System.Resources.ResXResourceReader, System.Windows.Forms, ...</resheader>
+    <resheader name="writer">System.Resources.ResXResourceWriter, System.Windows.Forms, ...</resheader>
+    <data name="Name1"><value>this is my long string</value><comment>this is a comment</comment></data>
+    <data name="Color1" type="System.Drawing.Color, System.Drawing">Blue</data>
+    <data name="Bitmap1" mimetype="application/x-microsoft.net.object.binary.base64">
+        <value>[base64 mime encoded serialized .NET Framework object]</value>
+    </data>
+    <data name="Icon1" type="System.Drawing.Icon, System.Drawing" mimetype="application/x-microsoft.net.object.bytearray.base64">
+        <value>[base64 mime encoded string representing a byte array form of the .NET Framework object]</value>
+        <comment>This is a comment</comment>
+    </data>
+
+    There are any number of "resheader" rows that contain simple
+    name/value pairs.
+
+    Each data row contains a name, and value. The row also contains a
+    type or mimetype. Type corresponds to a .NET class that support
+    text/value conversion through the TypeConverter architecture.
+    Classes that don't support this are serialized and stored with the
+    mimetype set.
+
+    The mimetype is used for serialized objects, and tells the
+    ResXResourceReader how to depersist the object. This is currently not
+    extensible. For a given mimetype the value must be set accordingly:
+
+    Note - application/x-microsoft.net.object.binary.base64 is the format
+    that the ResXResourceWriter will generate, however the reader can
+    read any of the formats listed below.
+
+    mimetype: application/x-microsoft.net.object.binary.base64
+    value   : The object must be serialized with
+            : System.Runtime.Serialization.Formatters.Binary.BinaryFormatter
+            : and then encoded with base64 encoding.
+    
+    mimetype: application/x-microsoft.net.object.soap.base64
+    value   : The object must be serialized with
+            : System.Runtime.Serialization.Formatters.Soap.SoapFormatter
+            : and then encoded with base64 encoding.
+
+    mimetype: application/x-microsoft.net.object.bytearray.base64
+    value   : The object must be serialized into a byte array
+            : using a System.ComponentModel.TypeConverter
+            : and then encoded with base64 encoding.
+    -->
+  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
+    <xsd:import namespace="http://www.w3.org/XML/1998/namespace" />
+    <xsd:element name="root" msdata:IsDataSet="true">
+      <xsd:complexType>
+        <xsd:choice maxOccurs="unbounded">
+          <xsd:element name="metadata">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" />
+              </xsd:sequence>
+              <xsd:attribute name="name" use="required" type="xsd:string" />
+              <xsd:attribute name="type" type="xsd:string" />
+              <xsd:attribute name="mimetype" type="xsd:string" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="assembly">
+            <xsd:complexType>
+              <xsd:attribute name="alias" type="xsd:string" />
+              <xsd:attribute name="name" type="xsd:string" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="data">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" msdata:Ordinal="1" />
+              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />
+              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="resheader">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" />
+            </xsd:complexType>
+          </xsd:element>
+        </xsd:choice>
+      </xsd:complexType>
+    </xsd:element>
+  </xsd:schema>
+  <resheader name="resmimetype">
+    <value>text/microsoft-resx</value>
+  </resheader>
+  <resheader name="version">
+    <value>2.0</value>
+  </resheader>
+  <resheader name="reader">
+    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+  <resheader name="writer">
+    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+</root>

BulletinBoard/BulletinBoard/ClientsForm/CreateClientsForm.Designer.cs

@@ -0,0 +1,201 @@
+namespace WebsiteForPlacingAds
+{
+    partial class CreateClientsForm
+    {
+        /// <summary>
+        ///  Required designer variable.
+        /// </summary>
+        private System.ComponentModel.IContainer components = null;
+
+        /// <summary>
+        ///  Clean up any resources being used.
+        /// </summary>
+        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
+        protected override void Dispose(bool disposing)
+        {
+            if (disposing && (components != null))
+            {
+                components.Dispose();
+            }
+            base.Dispose(disposing);
+        }
+
+        #region Windows Form Designer generated code
+
+        /// <summary>
+        ///  Required method for Designer support - do not modify
+        ///  the contents of this method with the code editor.
+        /// </summary>
+        private void InitializeComponent()
+        {
+            this.buttonCreateClient = new System.Windows.Forms.Button();
+            this.labelName = new System.Windows.Forms.Label();
+            this.textBoxName = new System.Windows.Forms.TextBox();
+            this.textBoxSurname = new System.Windows.Forms.TextBox();
+            this.labelSurname = new System.Windows.Forms.Label();
+            this.textBoxPatronymic = new System.Windows.Forms.TextBox();
+            this.labelPatronymic = new System.Windows.Forms.Label();
+            this.labelDate = new System.Windows.Forms.Label();
+            this.textBoxEmail = new System.Windows.Forms.TextBox();
+            this.labelEmail = new System.Windows.Forms.Label();
+            this.labelPhoneNumber = new System.Windows.Forms.Label();
+            this.textBoxPhoneNumber = new System.Windows.Forms.TextBox();
+            this.textBoxDate = new System.Windows.Forms.TextBox();
+            this.SuspendLayout();
+            // 
+            // buttonCreateClient
+            // 
+            this.buttonCreateClient.Location = new System.Drawing.Point(43, 346);
+            this.buttonCreateClient.Margin = new System.Windows.Forms.Padding(3, 2, 3, 2);
+            this.buttonCreateClient.Name = "buttonCreateClient";
+            this.buttonCreateClient.Size = new System.Drawing.Size(239, 29);
+            this.buttonCreateClient.TabIndex = 0;
+            this.buttonCreateClient.Text = "Создать клиента";
+            this.buttonCreateClient.UseVisualStyleBackColor = true;
+            this.buttonCreateClient.Click += new System.EventHandler(this.buttonCreateClient_Click);
+            // 
+            // labelName
+            // 
+            this.labelName.AutoSize = true;
+            this.labelName.Location = new System.Drawing.Point(43, 8);
+            this.labelName.Name = "labelName";
+            this.labelName.Size = new System.Drawing.Size(31, 15);
+            this.labelName.TabIndex = 1;
+            this.labelName.Text = "Имя";
+            // 
+            // textBoxName
+            // 
+            this.textBoxName.Location = new System.Drawing.Point(43, 26);
+            this.textBoxName.Margin = new System.Windows.Forms.Padding(3, 2, 3, 2);
+            this.textBoxName.Name = "textBoxName";
+            this.textBoxName.Size = new System.Drawing.Size(239, 23);
+            this.textBoxName.TabIndex = 2;
+            // 
+            // textBoxSurname
+            // 
+            this.textBoxSurname.Location = new System.Drawing.Point(43, 72);
+            this.textBoxSurname.Margin = new System.Windows.Forms.Padding(3, 2, 3, 2);
+            this.textBoxSurname.Name = "textBoxSurname";
+            this.textBoxSurname.Size = new System.Drawing.Size(239, 23);
+            this.textBoxSurname.TabIndex = 4;
+            // 
+            // labelSurname
+            // 
+            this.labelSurname.AutoSize = true;
+            this.labelSurname.Location = new System.Drawing.Point(43, 55);
+            this.labelSurname.Name = "labelSurname";
+            this.labelSurname.Size = new System.Drawing.Size(58, 15);
+            this.labelSurname.TabIndex = 3;
+            this.labelSurname.Text = "Фамилия";
+            // 
+            // textBoxPatronymic
+            // 
+            this.textBoxPatronymic.Location = new System.Drawing.Point(43, 118);
+            this.textBoxPatronymic.Margin = new System.Windows.Forms.Padding(3, 2, 3, 2);
+            this.textBoxPatronymic.Name = "textBoxPatronymic";
+            this.textBoxPatronymic.Size = new System.Drawing.Size(239, 23);
+            this.textBoxPatronymic.TabIndex = 6;
+            // 
+            // labelPatronymic
+            // 
+            this.labelPatronymic.AutoSize = true;
+            this.labelPatronymic.Location = new System.Drawing.Point(43, 101);
+            this.labelPatronymic.Name = "labelPatronymic";
+            this.labelPatronymic.Size = new System.Drawing.Size(58, 15);
+            this.labelPatronymic.TabIndex = 5;
+            this.labelPatronymic.Text = "Отчество";
+            // 
+            // labelDate
+            // 
+            this.labelDate.AutoSize = true;
+            this.labelDate.Location = new System.Drawing.Point(43, 246);
+            this.labelDate.Name = "labelDate";
+            this.labelDate.Size = new System.Drawing.Size(105, 15);
+            this.labelDate.TabIndex = 9;
+            this.labelDate.Text = "Дата регистрации";
+            // 
+            // textBoxEmail
+            // 
+            this.textBoxEmail.Location = new System.Drawing.Point(43, 166);
+            this.textBoxEmail.Margin = new System.Windows.Forms.Padding(3, 2, 3, 2);
+            this.textBoxEmail.Name = "textBoxEmail";
+            this.textBoxEmail.Size = new System.Drawing.Size(239, 23);
+            this.textBoxEmail.TabIndex = 8;
+            // 
+            // labelEmail
+            // 
+            this.labelEmail.AutoSize = true;
+            this.labelEmail.Location = new System.Drawing.Point(43, 148);
+            this.labelEmail.Name = "labelEmail";
+            this.labelEmail.Size = new System.Drawing.Size(41, 15);
+            this.labelEmail.TabIndex = 7;
+            this.labelEmail.Text = "Почта";
+            // 
+            // labelPhoneNumber
+            // 
+            this.labelPhoneNumber.AutoSize = true;
+            this.labelPhoneNumber.Location = new System.Drawing.Point(43, 196);
+            this.labelPhoneNumber.Name = "labelPhoneNumber";
+            this.labelPhoneNumber.Size = new System.Drawing.Size(101, 15);
+            this.labelPhoneNumber.TabIndex = 13;
+            this.labelPhoneNumber.Text = "Номер телефона";
+            // 
+            // textBoxPhoneNumber
+            // 
+            this.textBoxPhoneNumber.Location = new System.Drawing.Point(43, 213);
+            this.textBoxPhoneNumber.Margin = new System.Windows.Forms.Padding(3, 2, 3, 2);
+            this.textBoxPhoneNumber.Name = "textBoxPhoneNumber";
+            this.textBoxPhoneNumber.Size = new System.Drawing.Size(239, 23);
+            this.textBoxPhoneNumber.TabIndex = 14;
+            // 
+            // textBoxDate
+            // 
+            this.textBoxDate.Location = new System.Drawing.Point(43, 263);
+            this.textBoxDate.Margin = new System.Windows.Forms.Padding(3, 2, 3, 2);
+            this.textBoxDate.Name = "textBoxDate";
+            this.textBoxDate.Size = new System.Drawing.Size(239, 23);
+            this.textBoxDate.TabIndex = 15;
+            // 
+            // CreateClientsForm
+            // 
+            this.AutoScaleDimensions = new System.Drawing.SizeF(7F, 15F);
+            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
+            this.ClientSize = new System.Drawing.Size(324, 398);
+            this.Controls.Add(this.textBoxDate);
+            this.Controls.Add(this.textBoxPhoneNumber);
+            this.Controls.Add(this.labelPhoneNumber);
+            this.Controls.Add(this.labelDate);
+            this.Controls.Add(this.textBoxEmail);
+            this.Controls.Add(this.labelEmail);
+            this.Controls.Add(this.textBoxPatronymic);
+            this.Controls.Add(this.labelPatronymic);
+            this.Controls.Add(this.textBoxSurname);
+            this.Controls.Add(this.labelSurname);
+            this.Controls.Add(this.textBoxName);
+            this.Controls.Add(this.labelName);
+            this.Controls.Add(this.buttonCreateClient);
+            this.Margin = new System.Windows.Forms.Padding(3, 2, 3, 2);
+            this.Name = "CreateClientsForm";
+            this.Text = "Клиенты";
+            this.ResumeLayout(false);
+            this.PerformLayout();
+
+        }
+
+        #endregion
+
+        private Button buttonCreateClient;
+        private Label labelName;
+        private TextBox textBoxName;
+        private TextBox textBoxSurname;
+        private Label labelSurname;
+        private TextBox textBoxPatronymic;
+        private Label labelPatronymic;
+        private Label labelDate;
+        private TextBox textBoxEmail;
+        private Label labelEmail;
+        private Label labelPhoneNumber;
+        private TextBox textBoxPhoneNumber;
+        private TextBox textBoxDate;
+    }
+}

BulletinBoard/BulletinBoard/ClientsForm/CreateClientsForm.cs

@@ -0,0 +1,45 @@
+using System.Data;
+
+namespace WebsiteForPlacingAds
+{
+    public partial class CreateClientsForm : Form
+    {
+        //PostgreSqlDatabase psd;
+        AbstractManagmentDatabase managmentDatabase;
+        public CreateClientsForm(AbstractManagmentDatabase managmentDatabase)
+        {
+            InitializeComponent();
+            this.managmentDatabase = managmentDatabase;
+        }
+
+        private void buttonCreateClient_Click(object sender, EventArgs e)
+        {
+            string name = textBoxName.Text;
+            string surname = textBoxSurname.Text;
+            string patronymic = textBoxPatronymic.Text;
+            string email = textBoxEmail.Text;
+            string phoneNumber = textBoxPhoneNumber.Text;
+            string date = textBoxDate.Text;
+
+            try
+            {
+                DateTime start = DateTime.Now;
+
+                if (patronymic != null) 
+                    managmentDatabase.insertInto("clients", $"'{name}'", $"'{surname}'", $"'{patronymic}'", $"'{email}'", $"{phoneNumber}", $"'{date}'");
+                else managmentDatabase.insertInto("clients", $"'{name}'", $"'{surname}'", $"{patronymic}", $"'{email}'", $"{phoneNumber}", $"'{date}'");
+
+                DateTime end = DateTime.Now;
+                TimeSpan duration = end - start;
+                MessageBox.Show($"Äîáàâëåíî! Âðåìÿ âûïîëíåíèÿ: {duration.TotalMilliseconds} ìñ");
+
+                // Çàêðûòü òåêóùóþ ôîðìó ïîñëå âûïîëíåíèÿ äåéñòâèé
+                this.Close();
+            }
+            catch (Exception ex)
+            {
+                MessageBox.Show("Íå óäàëîñü äîáàâèòü");
+            }
+        }
+    }
+}

BulletinBoard/BulletinBoard/ClientsForm/CreateClientsForm.resx

@@ -0,0 +1,60 @@
+<root>
+  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
+    <xsd:import namespace="http://www.w3.org/XML/1998/namespace" />
+    <xsd:element name="root" msdata:IsDataSet="true">
+      <xsd:complexType>
+        <xsd:choice maxOccurs="unbounded">
+          <xsd:element name="metadata">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" />
+              </xsd:sequence>
+              <xsd:attribute name="name" use="required" type="xsd:string" />
+              <xsd:attribute name="type" type="xsd:string" />
+              <xsd:attribute name="mimetype" type="xsd:string" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="assembly">
+            <xsd:complexType>
+              <xsd:attribute name="alias" type="xsd:string" />
+              <xsd:attribute name="name" type="xsd:string" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="data">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" msdata:Ordinal="1" />
+              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />
+              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="resheader">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" />
+            </xsd:complexType>
+          </xsd:element>
+        </xsd:choice>
+      </xsd:complexType>
+    </xsd:element>
+  </xsd:schema>
+  <resheader name="resmimetype">
+    <value>text/microsoft-resx</value>
+  </resheader>
+  <resheader name="version">
+    <value>2.0</value>
+  </resheader>
+  <resheader name="reader">
+    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+  <resheader name="writer">
+    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+</root>

BulletinBoard/BulletinBoard/ClientsForm/DeleteClientsForm.Designer.cs

@@ -0,0 +1,87 @@
+namespace WebsiteForPlacingAds
+{
+    partial class DeleteClientsForm
+    {
+        /// <summary>
+        /// Required designer variable.
+        /// </summary>
+        private System.ComponentModel.IContainer components = null;
+
+        /// <summary>
+        /// Clean up any resources being used.
+        /// </summary>
+        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
+        protected override void Dispose(bool disposing)
+        {
+            if (disposing && (components != null))
+            {
+                components.Dispose();
+            }
+            base.Dispose(disposing);
+        }
+
+        #region Windows Form Designer generated code
+
+        /// <summary>
+        /// Required method for Designer support - do not modify
+        /// the contents of this method with the code editor.
+        /// </summary>
+        private void InitializeComponent()
+        {
+            this.label1 = new System.Windows.Forms.Label();
+            this.buttonDeleteClient = new System.Windows.Forms.Button();
+            this.comboBoxDeleteClients = new System.Windows.Forms.ComboBox();
+            this.SuspendLayout();
+            // 
+            // label1
+            // 
+            this.label1.AutoSize = true;
+            this.label1.Location = new System.Drawing.Point(70, 16);
+            this.label1.Name = "label1";
+            this.label1.Size = new System.Drawing.Size(266, 15);
+            this.label1.TabIndex = 0;
+            this.label1.Text = "Выберите объявление, которое хотите удалить";
+            // 
+            // buttonDeleteClient
+            // 
+            this.buttonDeleteClient.Location = new System.Drawing.Point(132, 85);
+            this.buttonDeleteClient.Margin = new System.Windows.Forms.Padding(3, 2, 3, 2);
+            this.buttonDeleteClient.Name = "buttonDeleteClient";
+            this.buttonDeleteClient.Size = new System.Drawing.Size(163, 28);
+            this.buttonDeleteClient.TabIndex = 1;
+            this.buttonDeleteClient.Text = "Удалить";
+            this.buttonDeleteClient.UseVisualStyleBackColor = true;
+            this.buttonDeleteClient.Click += new System.EventHandler(this.buttonDeleteAd_Click);
+            // 
+            // comboBoxDeleteClients
+            // 
+            this.comboBoxDeleteClients.FormattingEnabled = true;
+            this.comboBoxDeleteClients.Location = new System.Drawing.Point(35, 48);
+            this.comboBoxDeleteClients.Margin = new System.Windows.Forms.Padding(3, 2, 3, 2);
+            this.comboBoxDeleteClients.Name = "comboBoxDeleteClients";
+            this.comboBoxDeleteClients.Size = new System.Drawing.Size(367, 23);
+            this.comboBoxDeleteClients.TabIndex = 2;
+            // 
+            // DeleteClientsForm
+            // 
+            this.AutoScaleDimensions = new System.Drawing.SizeF(7F, 15F);
+            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
+            this.ClientSize = new System.Drawing.Size(442, 131);
+            this.Controls.Add(this.comboBoxDeleteClients);
+            this.Controls.Add(this.buttonDeleteClient);
+            this.Controls.Add(this.label1);
+            this.Margin = new System.Windows.Forms.Padding(3, 2, 3, 2);
+            this.Name = "DeleteClientsForm";
+            this.Text = "Удалить объявление";
+            this.ResumeLayout(false);
+            this.PerformLayout();
+
+        }
+
+        #endregion
+
+        private Label label1;
+        private Button buttonDeleteClient;
+        private ComboBox comboBoxDeleteClients;
+    }
+}

BulletinBoard/BulletinBoard/ClientsForm/DeleteClientsForm.cs

@@ -0,0 +1,68 @@
+using System;
+using System.Collections.Generic;
+using System.ComponentModel;
+using System.Data;
+using System.Drawing;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using System.Windows.Forms;
+
+namespace WebsiteForPlacingAds
+{
+    public partial class DeleteClientsForm : Form
+    {
+        AbstractManagmentDatabase managmentDatabase;
+        private int setval_seq;
+        public DeleteClientsForm(AbstractManagmentDatabase managmentDatabase)
+        {
+            InitializeComponent();
+            this.managmentDatabase = managmentDatabase;
+            LoadData();
+        }
+
+        private void buttonDeleteAd_Click(object sender, EventArgs e)
+        {
+            string[] clients = comboBoxDeleteClients.SelectedItem.ToString().Split("|");
+            string client_id = clients[0].Trim();
+            //string query = $"DELETE FROM ADS WHERE ads_id = {ad_id}";
+            //string query_seq_reduction = $"SELECT setval('seq_ads', {setval_seq - 1});";
+            try
+            {
+                DateTime start = DateTime.Now;
+
+                managmentDatabase.deleteEntry("clients", int.Parse(client_id));
+                LoadData();
+                if (setval_seq > 0)  managmentDatabase.reduceSeq("seq_clients", setval_seq);
+
+                DateTime end = DateTime.Now;
+                TimeSpan duration = end - start;
+
+                MessageBox.Show($"Удалено! Время выполнения: {duration.TotalMilliseconds} мс");
+            }
+            catch (Exception ex)
+            {
+                MessageBox.Show("Не удалось удалить");
+            }
+        }
+        public void LoadData()
+        {
+            comboBoxDeleteClients.Items.Clear();
+            DataTable result = managmentDatabase.getAllEntry("Clients");
+            setval_seq = result.Rows.Count;
+            string Clients = "";
+            for (int i = 0; i < result.Rows.Count; i++)
+            {
+                setval_seq = Math.Max(Convert.ToInt32(managmentDatabase.getRowTableById(result, "clients_id", i)), setval_seq);
+                Clients = managmentDatabase.getRowTableById(result, "clients_id", i).ToString() + " | " +
+                                managmentDatabase.getRowTableById(result, "name", i).ToString() + " | " +
+                                managmentDatabase.getRowTableById(result, "surname", i).ToString() + " | " +
+                                managmentDatabase.getRowTableById(result, "patronymic", i).ToString() + " | " +
+                                managmentDatabase.getRowTableById(result, "email", i).ToString() + " | " +
+                                managmentDatabase.getRowTableById(result, "phone_number", i).ToString() + " | " +
+                                ((DateTime)managmentDatabase.getRowTableById(result, "registration_date", i)).ToString("dd.MM.yyy") + "\n";
+                comboBoxDeleteClients.Items.Add(Clients);
+            }
+        }
+    }
+}

BulletinBoard/BulletinBoard/ClientsForm/DeleteClientsForm.resx

@@ -0,0 +1,60 @@
+<root>
+  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
+    <xsd:import namespace="http://www.w3.org/XML/1998/namespace" />
+    <xsd:element name="root" msdata:IsDataSet="true">
+      <xsd:complexType>
+        <xsd:choice maxOccurs="unbounded">
+          <xsd:element name="metadata">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" />
+              </xsd:sequence>
+              <xsd:attribute name="name" use="required" type="xsd:string" />
+              <xsd:attribute name="type" type="xsd:string" />
+              <xsd:attribute name="mimetype" type="xsd:string" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="assembly">
+            <xsd:complexType>
+              <xsd:attribute name="alias" type="xsd:string" />
+              <xsd:attribute name="name" type="xsd:string" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="data">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" msdata:Ordinal="1" />
+              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />
+              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="resheader">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" />
+            </xsd:complexType>
+          </xsd:element>
+        </xsd:choice>
+      </xsd:complexType>
+    </xsd:element>
+  </xsd:schema>
+  <resheader name="resmimetype">
+    <value>text/microsoft-resx</value>
+  </resheader>
+  <resheader name="version">
+    <value>2.0</value>
+  </resheader>
+  <resheader name="reader">
+    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+  <resheader name="writer">
+    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+</root>

BulletinBoard/BulletinBoard/ClientsForm/ListClientsForm.Designer.cs

@@ -0,0 +1,75 @@
+namespace WebsiteForPlacingAds
+{
+    partial class ListClientsForm
+    {
+        /// <summary>
+        /// Required designer variable.
+        /// </summary>
+        private System.ComponentModel.IContainer components = null;
+
+        /// <summary>
+        /// Clean up any resources being used.
+        /// </summary>
+        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
+        protected override void Dispose(bool disposing)
+        {
+            if (disposing && (components != null))
+            {
+                components.Dispose();
+            }
+            base.Dispose(disposing);
+        }
+
+        #region Windows Form Designer generated code
+
+        /// <summary>
+        /// Required method for Designer support - do not modify
+        /// the contents of this method with the code editor.
+        /// </summary>
+        private void InitializeComponent()
+        {
+            this.label1 = new System.Windows.Forms.Label();
+            this.labelListClients = new System.Windows.Forms.Label();
+            this.SuspendLayout();
+            // 
+            // label1
+            // 
+            this.label1.AutoSize = true;
+            this.label1.BackColor = System.Drawing.SystemColors.Control;
+            this.label1.Font = new System.Drawing.Font("Segoe UI", 11F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point);
+            this.label1.Location = new System.Drawing.Point(10, 7);
+            this.label1.Name = "label1";
+            this.label1.Size = new System.Drawing.Size(127, 20);
+            this.label1.TabIndex = 0;
+            this.label1.Text = "Список клиентов";
+            // 
+            // labelListClients
+            // 
+            this.labelListClients.AutoSize = true;
+            this.labelListClients.Font = new System.Drawing.Font("Segoe UI", 10F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point);
+            this.labelListClients.Location = new System.Drawing.Point(10, 35);
+            this.labelListClients.Name = "labelListClients";
+            this.labelListClients.Size = new System.Drawing.Size(0, 19);
+            this.labelListClients.TabIndex = 1;
+            // 
+            // ListClientsForm
+            // 
+            this.AutoScaleDimensions = new System.Drawing.SizeF(7F, 15F);
+            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
+            this.ClientSize = new System.Drawing.Size(700, 338);
+            this.Controls.Add(this.labelListClients);
+            this.Controls.Add(this.label1);
+            this.Margin = new System.Windows.Forms.Padding(3, 2, 3, 2);
+            this.Name = "ListClientsForm";
+            this.Text = "Список клиентов";
+            this.ResumeLayout(false);
+            this.PerformLayout();
+
+        }
+
+        #endregion
+
+        private Label label1;
+        private Label labelListClients;
+    }
+}

BulletinBoard/BulletinBoard/ClientsForm/ListClientsForm.cs

@@ -0,0 +1,48 @@
+using System;
+using System.Collections.Generic;
+using System.ComponentModel;
+using System.Data;
+using System.Drawing;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using System.Windows.Forms;
+using System.Windows.Forms.VisualStyles;
+
+namespace WebsiteForPlacingAds
+{
+    public partial class ListClientsForm : Form
+    {
+        AbstractManagmentDatabase managmentDatabase;
+        public ListClientsForm(AbstractManagmentDatabase managmentDatabase)
+        {
+            InitializeComponent();
+            this.managmentDatabase = managmentDatabase;
+            LoadData();
+        }
+
+        private void LoadData()
+        {
+            DateTime start = DateTime.Now;
+
+            DataTable result = managmentDatabase.getAllEntry("clients");
+            string listClients = "";
+            for (int i = 0; i < result.Rows.Count; i++)
+            {
+                listClients += managmentDatabase.getRowTableById(result, "clients_id", i).ToString() + " | " +
+                                managmentDatabase.getRowTableById(result, "name", i).ToString() + " | " +
+                                managmentDatabase.getRowTableById(result, "surname", i).ToString() + " | " +
+                                managmentDatabase.getRowTableById(result, "patronymic", i).ToString() + " | " +
+                                managmentDatabase.getRowTableById(result, "email", i).ToString() + " | " +
+                                managmentDatabase.getRowTableById(result, "phone_number", i).ToString() + " | " +
+                                ((DateTime)managmentDatabase.getRowTableById(result, "registration_date", i)).ToString("dd.MM.yyy") + "\n";
+            }
+            labelListClients.Text = listClients;
+
+
+            DateTime end = DateTime.Now;
+            TimeSpan duration = end - start;
+            MessageBox.Show($"Список загружен! Время выполнения: {duration.TotalMilliseconds} мс");
+        }
+    }
+}

BulletinBoard/BulletinBoard/ClientsForm/ListClientsForm.resx

@@ -0,0 +1,60 @@
+<root>
+  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
+    <xsd:import namespace="http://www.w3.org/XML/1998/namespace" />
+    <xsd:element name="root" msdata:IsDataSet="true">
+      <xsd:complexType>
+        <xsd:choice maxOccurs="unbounded">
+          <xsd:element name="metadata">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" />
+              </xsd:sequence>
+              <xsd:attribute name="name" use="required" type="xsd:string" />
+              <xsd:attribute name="type" type="xsd:string" />
+              <xsd:attribute name="mimetype" type="xsd:string" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="assembly">
+            <xsd:complexType>
+              <xsd:attribute name="alias" type="xsd:string" />
+              <xsd:attribute name="name" type="xsd:string" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="data">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" msdata:Ordinal="1" />
+              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />
+              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="resheader">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" />
+            </xsd:complexType>
+          </xsd:element>
+        </xsd:choice>
+      </xsd:complexType>
+    </xsd:element>
+  </xsd:schema>
+  <resheader name="resmimetype">
+    <value>text/microsoft-resx</value>
+  </resheader>
+  <resheader name="version">
+    <value>2.0</value>
+  </resheader>
+  <resheader name="reader">
+    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+  <resheader name="writer">
+    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+</root>

BulletinBoard/BulletinBoard/ClientsForm/UpdateClientsForm.Designer.cs

@@ -0,0 +1,225 @@
+namespace WebsiteForPlacingAds
+{
+    partial class UpdateClientsForm
+    {
+        /// <summary>
+        /// Required designer variable.
+        /// </summary>
+        private System.ComponentModel.IContainer components = null;
+
+        /// <summary>
+        /// Clean up any resources being used.
+        /// </summary>
+        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
+        protected override void Dispose(bool disposing)
+        {
+            if (disposing && (components != null))
+            {
+                components.Dispose();
+            }
+            base.Dispose(disposing);
+        }
+
+        #region Windows Form Designer generated code
+
+        /// <summary>
+        /// Required method for Designer support - do not modify
+        /// the contents of this method with the code editor.
+        /// </summary>
+        private void InitializeComponent()
+        {
+            this.buttonUpdateClient = new System.Windows.Forms.Button();
+            this.label1 = new System.Windows.Forms.Label();
+            this.comboBoxUpdateClient = new System.Windows.Forms.ComboBox();
+            this.textBoxDate = new System.Windows.Forms.TextBox();
+            this.textBoxPhoneNumber = new System.Windows.Forms.TextBox();
+            this.labelPhoneNumber = new System.Windows.Forms.Label();
+            this.labelDate = new System.Windows.Forms.Label();
+            this.textBoxEmail = new System.Windows.Forms.TextBox();
+            this.labelEmail = new System.Windows.Forms.Label();
+            this.textBoxPatronymic = new System.Windows.Forms.TextBox();
+            this.labelPatronymic = new System.Windows.Forms.Label();
+            this.textBoxSurname = new System.Windows.Forms.TextBox();
+            this.labelSurname = new System.Windows.Forms.Label();
+            this.textBoxName = new System.Windows.Forms.TextBox();
+            this.labelName = new System.Windows.Forms.Label();
+            this.SuspendLayout();
+            // 
+            // buttonUpdateClient
+            // 
+            this.buttonUpdateClient.Location = new System.Drawing.Point(81, 407);
+            this.buttonUpdateClient.Margin = new System.Windows.Forms.Padding(3, 2, 3, 2);
+            this.buttonUpdateClient.Name = "buttonUpdateClient";
+            this.buttonUpdateClient.Size = new System.Drawing.Size(239, 29);
+            this.buttonUpdateClient.TabIndex = 18;
+            this.buttonUpdateClient.Text = "Обновить клиента";
+            this.buttonUpdateClient.UseVisualStyleBackColor = true;
+            this.buttonUpdateClient.Click += new System.EventHandler(this.buttonUpdateClient_Click);
+            // 
+            // label1
+            // 
+            this.label1.AutoSize = true;
+            this.label1.Location = new System.Drawing.Point(51, 15);
+            this.label1.Name = "label1";
+            this.label1.Size = new System.Drawing.Size(259, 15);
+            this.label1.TabIndex = 33;
+            this.label1.Text = "Выберите клиента, которого хотите обновить";
+            // 
+            // comboBoxUpdateClient
+            // 
+            this.comboBoxUpdateClient.FormattingEnabled = true;
+            this.comboBoxUpdateClient.Location = new System.Drawing.Point(10, 39);
+            this.comboBoxUpdateClient.Margin = new System.Windows.Forms.Padding(3, 2, 3, 2);
+            this.comboBoxUpdateClient.Name = "comboBoxUpdateClient";
+            this.comboBoxUpdateClient.Size = new System.Drawing.Size(377, 23);
+            this.comboBoxUpdateClient.TabIndex = 34;
+            this.comboBoxUpdateClient.SelectedIndexChanged += new System.EventHandler(this.comboBoxUpdateClient_SelectedIndexChanged);
+            // 
+            // textBoxDate
+            // 
+            this.textBoxDate.Location = new System.Drawing.Point(79, 326);
+            this.textBoxDate.Margin = new System.Windows.Forms.Padding(3, 2, 3, 2);
+            this.textBoxDate.Name = "textBoxDate";
+            this.textBoxDate.Size = new System.Drawing.Size(239, 23);
+            this.textBoxDate.TabIndex = 47;
+            // 
+            // textBoxPhoneNumber
+            // 
+            this.textBoxPhoneNumber.Location = new System.Drawing.Point(79, 276);
+            this.textBoxPhoneNumber.Margin = new System.Windows.Forms.Padding(3, 2, 3, 2);
+            this.textBoxPhoneNumber.Name = "textBoxPhoneNumber";
+            this.textBoxPhoneNumber.Size = new System.Drawing.Size(239, 23);
+            this.textBoxPhoneNumber.TabIndex = 46;
+            // 
+            // labelPhoneNumber
+            // 
+            this.labelPhoneNumber.AutoSize = true;
+            this.labelPhoneNumber.Location = new System.Drawing.Point(79, 259);
+            this.labelPhoneNumber.Name = "labelPhoneNumber";
+            this.labelPhoneNumber.Size = new System.Drawing.Size(101, 15);
+            this.labelPhoneNumber.TabIndex = 45;
+            this.labelPhoneNumber.Text = "Номер телефона";
+            // 
+            // labelDate
+            // 
+            this.labelDate.AutoSize = true;
+            this.labelDate.Location = new System.Drawing.Point(79, 309);
+            this.labelDate.Name = "labelDate";
+            this.labelDate.Size = new System.Drawing.Size(105, 15);
+            this.labelDate.TabIndex = 43;
+            this.labelDate.Text = "Дата регистрации";
+            // 
+            // textBoxEmail
+            // 
+            this.textBoxEmail.Location = new System.Drawing.Point(79, 229);
+            this.textBoxEmail.Margin = new System.Windows.Forms.Padding(3, 2, 3, 2);
+            this.textBoxEmail.Name = "textBoxEmail";
+            this.textBoxEmail.Size = new System.Drawing.Size(239, 23);
+            this.textBoxEmail.TabIndex = 42;
+            // 
+            // labelEmail
+            // 
+            this.labelEmail.AutoSize = true;
+            this.labelEmail.Location = new System.Drawing.Point(79, 211);
+            this.labelEmail.Name = "labelEmail";
+            this.labelEmail.Size = new System.Drawing.Size(41, 15);
+            this.labelEmail.TabIndex = 41;
+            this.labelEmail.Text = "Почта";
+            // 
+            // textBoxPatronymic
+            // 
+            this.textBoxPatronymic.Location = new System.Drawing.Point(79, 181);
+            this.textBoxPatronymic.Margin = new System.Windows.Forms.Padding(3, 2, 3, 2);
+            this.textBoxPatronymic.Name = "textBoxPatronymic";
+            this.textBoxPatronymic.Size = new System.Drawing.Size(239, 23);
+            this.textBoxPatronymic.TabIndex = 40;
+            // 
+            // labelPatronymic
+            // 
+            this.labelPatronymic.AutoSize = true;
+            this.labelPatronymic.Location = new System.Drawing.Point(79, 164);
+            this.labelPatronymic.Name = "labelPatronymic";
+            this.labelPatronymic.Size = new System.Drawing.Size(58, 15);
+            this.labelPatronymic.TabIndex = 39;
+            this.labelPatronymic.Text = "Отчество";
+            // 
+            // textBoxSurname
+            // 
+            this.textBoxSurname.Location = new System.Drawing.Point(79, 135);
+            this.textBoxSurname.Margin = new System.Windows.Forms.Padding(3, 2, 3, 2);
+            this.textBoxSurname.Name = "textBoxSurname";
+            this.textBoxSurname.Size = new System.Drawing.Size(239, 23);
+            this.textBoxSurname.TabIndex = 38;
+            // 
+            // labelSurname
+            // 
+            this.labelSurname.AutoSize = true;
+            this.labelSurname.Location = new System.Drawing.Point(79, 118);
+            this.labelSurname.Name = "labelSurname";
+            this.labelSurname.Size = new System.Drawing.Size(58, 15);
+            this.labelSurname.TabIndex = 37;
+            this.labelSurname.Text = "Фамилия";
+            // 
+            // textBoxName
+            // 
+            this.textBoxName.Location = new System.Drawing.Point(79, 89);
+            this.textBoxName.Margin = new System.Windows.Forms.Padding(3, 2, 3, 2);
+            this.textBoxName.Name = "textBoxName";
+            this.textBoxName.Size = new System.Drawing.Size(239, 23);
+            this.textBoxName.TabIndex = 36;
+            // 
+            // labelName
+            // 
+            this.labelName.AutoSize = true;
+            this.labelName.Location = new System.Drawing.Point(79, 71);
+            this.labelName.Name = "labelName";
+            this.labelName.Size = new System.Drawing.Size(31, 15);
+            this.labelName.TabIndex = 35;
+            this.labelName.Text = "Имя";
+            // 
+            // UpdateClientsForm
+            // 
+            this.AutoScaleDimensions = new System.Drawing.SizeF(7F, 15F);
+            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
+            this.ClientSize = new System.Drawing.Size(397, 464);
+            this.Controls.Add(this.textBoxDate);
+            this.Controls.Add(this.textBoxPhoneNumber);
+            this.Controls.Add(this.labelPhoneNumber);
+            this.Controls.Add(this.labelDate);
+            this.Controls.Add(this.textBoxEmail);
+            this.Controls.Add(this.labelEmail);
+            this.Controls.Add(this.textBoxPatronymic);
+            this.Controls.Add(this.labelPatronymic);
+            this.Controls.Add(this.textBoxSurname);
+            this.Controls.Add(this.labelSurname);
+            this.Controls.Add(this.textBoxName);
+            this.Controls.Add(this.labelName);
+            this.Controls.Add(this.comboBoxUpdateClient);
+            this.Controls.Add(this.label1);
+            this.Controls.Add(this.buttonUpdateClient);
+            this.Margin = new System.Windows.Forms.Padding(3, 2, 3, 2);
+            this.Name = "UpdateClientsForm";
+            this.Text = "Обновить клиента";
+            this.ResumeLayout(false);
+            this.PerformLayout();
+
+        }
+
+        #endregion
+        private Button buttonUpdateClient;
+        private Label label1;
+        private ComboBox comboBoxUpdateClient;
+        private TextBox textBoxDate;
+        private TextBox textBoxPhoneNumber;
+        private Label labelPhoneNumber;
+        private Label labelDate;
+        private TextBox textBoxEmail;
+        private Label labelEmail;
+        private TextBox textBoxPatronymic;
+        private Label labelPatronymic;
+        private TextBox textBoxSurname;
+        private Label labelSurname;
+        private TextBox textBoxName;
+        private Label labelName;
+    }
+}

BulletinBoard/BulletinBoard/ClientsForm/UpdateClientsForm.cs

@@ -0,0 +1,110 @@
+using System;
+using System.Collections.Generic;
+using System.ComponentModel;
+using System.Data;
+using System.Drawing;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using System.Windows.Forms;
+
+namespace WebsiteForPlacingAds
+{
+    public partial class UpdateClientsForm : Form
+    {
+        AbstractManagmentDatabase managmentDatabase;
+        public UpdateClientsForm(AbstractManagmentDatabase managmentDatabase)
+        {
+            InitializeComponent();
+            this.managmentDatabase = managmentDatabase;
+            LoadData();
+        }
+        public void LoadData()
+        {
+            comboBoxUpdateClient.Items.Clear();
+            DataTable result = managmentDatabase.getAllEntry("Clients");
+            string Clients = "";
+            for (int i = 0; i < result.Rows.Count; i++)
+            {
+                Clients = result.Rows[i]["clients_id"].ToString() + " | " +
+                                (string)result.Rows[i]["name"] + " | " +
+                                result.Rows[i]["surname"].ToString() + " | " +
+                                (string)result.Rows[i]["patronymic"] + " | " +
+                                result.Rows[i]["email"].ToString() + " | " +
+                                result.Rows[i]["phone_number"].ToString() + " | " +
+                                ((DateTime)result.Rows[i]["registration_date"]).ToString("dd.MM.yyyy") + "\n";
+                comboBoxUpdateClient.Items.Add(Clients);
+            }
+        }
+        private void buttonUpdateClient_Click(object sender, EventArgs e)
+        {
+            string[] selectedClients = comboBoxUpdateClient.SelectedItem.ToString().Split("|");
+            int clients_id = int.Parse(selectedClients[0].Trim());
+
+            string query = $"UPDATE clients SET ";
+            int len = query.Length;
+
+
+            string oldName = managmentDatabase.getRowTableById("clients", "name", clients_id).ToString();
+            string oldSurname = managmentDatabase.getRowTableById("clients", "surname", clients_id).ToString();
+            string oldPatronymic = managmentDatabase.getRowTableById("clients", "patronymic", clients_id).ToString();
+            string oldEmail = managmentDatabase.getRowTableById("clients", "email", clients_id).ToString();
+            string oldPhoneNumber = managmentDatabase.getRowTableById("clients", "phone_number", clients_id).ToString();
+            string oldDate = ((DateTime)managmentDatabase.getRowTableById("clients", "registration_date", clients_id)).ToString("dd.MM.yyyy");
+
+            string newName = textBoxName.Text;
+            string newSurname = textBoxSurname.Text;
+            string newPatronymic = textBoxPatronymic.Text;
+            string newEmail = textBoxEmail.Text;
+            string newPhoneNumber = textBoxPhoneNumber.Text;
+            string newDate = textBoxDate.Text;
+
+
+            query = oldName == newName ? query : query + $"name = '{newName}', ";
+            query = oldSurname == newSurname ? query : query + $"surname = '{newSurname}', ";
+            query = oldPatronymic == newPatronymic ? query : query + $"patronymic = '{newPatronymic}', ";
+            query = oldEmail == newEmail ? query : query + $"email = '{newEmail}', ";
+            query = oldPhoneNumber == newPhoneNumber ? query : query + $"phone_number = {newPhoneNumber}, ";
+            query = oldDate == newDate ? query : query + $"registration_date = '{newDate}', ";
+
+            if (len != query.Length)
+            {
+                query = query.TrimEnd(' ');
+                query = query.TrimEnd(',');
+                query += $" WHERE Clients_ID = {clients_id};";
+            }
+            try
+            {
+                DateTime start = DateTime.Now;
+
+                managmentDatabase.ExecuteNonQuery(query);
+
+                DateTime end = DateTime.Now;
+                TimeSpan duration = end - start;
+                MessageBox.Show($"Данные успешно обновлены! Время выполнения: {duration.TotalMilliseconds} мс");
+            }
+            catch (Exception)
+            {
+
+                MessageBox.Show("Данные не обновились");
+            }
+        }
+        public void LoadDataSelectedItem(int clients_id)
+        {
+            DataTable result = managmentDatabase.getEntryById("clients", clients_id);
+            textBoxName.Text = managmentDatabase.getRowTableById(result, "name", 0).ToString();
+            textBoxSurname.Text = managmentDatabase.getRowTableById(result, "surname", 0).ToString();
+            textBoxPatronymic.Text = managmentDatabase.getRowTableById(result, "patronymic", 0).ToString();
+            textBoxEmail.Text = managmentDatabase.getRowTableById(result, "email", 0).ToString();
+            textBoxPhoneNumber.Text = managmentDatabase.getRowTableById(result, "phone_number", 0).ToString();
+            textBoxDate.Text = ((DateTime)managmentDatabase.getRowTableById(result, "registration_date", 0)).ToString("dd.MM.yyyy");
+        }
+
+        private void comboBoxUpdateClient_SelectedIndexChanged(object sender, EventArgs e)
+        {
+            string[] selectedItems = comboBoxUpdateClient.SelectedItem.ToString().Split("|");
+            int clients_id = int.Parse(selectedItems[0].Trim());
+            LoadDataSelectedItem(clients_id);
+        }
+    }
+}

BulletinBoard/BulletinBoard/ClientsForm/UpdateClientsForm.resx

@@ -0,0 +1,60 @@
+<root>
+  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
+    <xsd:import namespace="http://www.w3.org/XML/1998/namespace" />
+    <xsd:element name="root" msdata:IsDataSet="true">
+      <xsd:complexType>
+        <xsd:choice maxOccurs="unbounded">
+          <xsd:element name="metadata">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" />
+              </xsd:sequence>
+              <xsd:attribute name="name" use="required" type="xsd:string" />
+              <xsd:attribute name="type" type="xsd:string" />
+              <xsd:attribute name="mimetype" type="xsd:string" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="assembly">
+            <xsd:complexType>
+              <xsd:attribute name="alias" type="xsd:string" />
+              <xsd:attribute name="name" type="xsd:string" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="data">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" msdata:Ordinal="1" />
+              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />
+              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="resheader">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" />
+            </xsd:complexType>
+          </xsd:element>
+        </xsd:choice>
+      </xsd:complexType>
+    </xsd:element>
+  </xsd:schema>
+  <resheader name="resmimetype">
+    <value>text/microsoft-resx</value>
+  </resheader>
+  <resheader name="version">
+    <value>2.0</value>
+  </resheader>
+  <resheader name="reader">
+    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+  <resheader name="writer">
+    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+</root>

BulletinBoard/BulletinBoard/MainForm.Designer.cs

@@ -0,0 +1,448 @@
+namespace WebsiteForPlacingAds
+{
+    partial class MainForm
+    {
+        /// <summary>
+        /// Required designer variable.
+        /// </summary>
+        private System.ComponentModel.IContainer components = null;
+
+        /// <summary>
+        /// Clean up any resources being used.
+        /// </summary>
+        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
+        protected override void Dispose(bool disposing)
+        {
+            if (disposing && (components != null))
+            {
+                components.Dispose();
+            }
+            base.Dispose(disposing);
+        }
+
+        #region Windows Form Designer generated code
+
+        /// <summary>
+        /// Required method for Designer support - do not modify
+        /// the contents of this method with the code editor.
+        /// </summary>
+        private void InitializeComponent()
+        {
+            menuStrip1 = new MenuStrip();
+            клиентыToolStripMenuItem = new ToolStripMenuItem();
+            создатьКлиентаToolStripMenuItem = new ToolStripMenuItem();
+            удалитьКлиентаToolStripMenuItem = new ToolStripMenuItem();
+            изменитьДанныеКлиентаToolStripMenuItem = new ToolStripMenuItem();
+            списокКлиентвToolStripMenuItem = new ToolStripMenuItem();
+            объявленияToolStripMenuItem = new ToolStripMenuItem();
+            создатьОбъявлениеToolStripMenuItem = new ToolStripMenuItem();
+            удалитьОбъявлениеToolStripMenuItem = new ToolStripMenuItem();
+            изменитьОбъявлениеэToolStripMenuItem = new ToolStripMenuItem();
+            списокОбъявленийToolStripMenuItem = new ToolStripMenuItem();
+            категорииToolStripMenuItem = new ToolStripMenuItem();
+            создатьКатегориюToolStripMenuItem = new ToolStripMenuItem();
+            удалитьКатегориюToolStripMenuItem = new ToolStripMenuItem();
+            изменитьКатегориюToolStripMenuItem = new ToolStripMenuItem();
+            списокКатегорийToolStripMenuItem = new ToolStripMenuItem();
+            подкатегорииToolStripMenuItem = new ToolStripMenuItem();
+            создатьПодкатеориюToolStripMenuItem = new ToolStripMenuItem();
+            удалитьПодкатегориюToolStripMenuItem = new ToolStripMenuItem();
+            изменитьПодкатегориюToolStripMenuItem = new ToolStripMenuItem();
+            списокПодкатегоийToolStripMenuItem = new ToolStripMenuItem();
+            toolStripMenuItem1 = new ToolStripMenuItem();
+            toolStripMenuItem2 = new ToolStripMenuItem();
+            toolStripMenuItem3 = new ToolStripMenuItem();
+            toolStripMenuItem4 = new ToolStripMenuItem();
+            toolStripMenuItem5 = new ToolStripMenuItem();
+            label1 = new Label();
+            button1 = new Button();
+            panel1 = new Panel();
+            panel2 = new Panel();
+            button2 = new Button();
+            label2 = new Label();
+            panel3 = new Panel();
+            button3 = new Button();
+            label3 = new Label();
+            toolStripMenuItem6 = new ToolStripMenuItem();
+            toolStripMenuItem7 = new ToolStripMenuItem();
+            toolStripMenuItem8 = new ToolStripMenuItem();
+            toolStripMenuItem9 = new ToolStripMenuItem();
+            toolStripMenuItem10 = new ToolStripMenuItem();
+            menuStrip1.SuspendLayout();
+            panel1.SuspendLayout();
+            panel2.SuspendLayout();
+            panel3.SuspendLayout();
+            SuspendLayout();
+            // 
+            // menuStrip1
+            // 
+            menuStrip1.ImageScalingSize = new Size(20, 20);
+            menuStrip1.Items.AddRange(new ToolStripItem[] { клиентыToolStripMenuItem, объявленияToolStripMenuItem, категорииToolStripMenuItem, подкатегорииToolStripMenuItem, toolStripMenuItem1, toolStripMenuItem6 });
+            menuStrip1.Location = new Point(0, 0);
+            menuStrip1.Name = "menuStrip1";
+            menuStrip1.Padding = new Padding(5, 2, 0, 2);
+            menuStrip1.Size = new Size(700, 24);
+            menuStrip1.TabIndex = 0;
+            menuStrip1.Text = "menuStrip1";
+            // 
+            // клиентыToolStripMenuItem
+            // 
+            клиентыToolStripMenuItem.DropDownItems.AddRange(new ToolStripItem[] { создатьКлиентаToolStripMenuItem, удалитьКлиентаToolStripMenuItem, изменитьДанныеКлиентаToolStripMenuItem, списокКлиентвToolStripMenuItem });
+            клиентыToolStripMenuItem.Name = "клиентыToolStripMenuItem";
+            клиентыToolStripMenuItem.Size = new Size(67, 20);
+            клиентыToolStripMenuItem.Text = "Клиенты";
+            // 
+            // создатьКлиентаToolStripMenuItem
+            // 
+            создатьКлиентаToolStripMenuItem.Name = "создатьКлиентаToolStripMenuItem";
+            создатьКлиентаToolStripMenuItem.Size = new Size(219, 22);
+            создатьКлиентаToolStripMenuItem.Text = "Создать клиента";
+            создатьКлиентаToolStripMenuItem.Click += создатьКлиентаToolStripMenuItem_Click;
+            // 
+            // удалитьКлиентаToolStripMenuItem
+            // 
+            удалитьКлиентаToolStripMenuItem.Name = "удалитьКлиентаToolStripMenuItem";
+            удалитьКлиентаToolStripMenuItem.Size = new Size(219, 22);
+            удалитьКлиентаToolStripMenuItem.Text = "Удалить клиента";
+            удалитьКлиентаToolStripMenuItem.Click += удалитьКлиентаToolStripMenuItem_Click;
+            // 
+            // изменитьДанныеКлиентаToolStripMenuItem
+            // 
+            изменитьДанныеКлиентаToolStripMenuItem.Name = "изменитьДанныеКлиентаToolStripMenuItem";
+            изменитьДанныеКлиентаToolStripMenuItem.Size = new Size(219, 22);
+            изменитьДанныеКлиентаToolStripMenuItem.Text = "Изменить данные клиента";
+            изменитьДанныеКлиентаToolStripMenuItem.Click += изменитьДанныеКлиентаToolStripMenuItem_Click;
+            // 
+            // списокКлиентвToolStripMenuItem
+            // 
+            списокКлиентвToolStripMenuItem.Name = "списокКлиентвToolStripMenuItem";
+            списокКлиентвToolStripMenuItem.Size = new Size(219, 22);
+            списокКлиентвToolStripMenuItem.Text = "Список клиентов";
+            списокКлиентвToolStripMenuItem.Click += списокКлиентвToolStripMenuItem_Click;
+            // 
+            // объявленияToolStripMenuItem
+            // 
+            объявленияToolStripMenuItem.DropDownItems.AddRange(new ToolStripItem[] { создатьОбъявлениеToolStripMenuItem, удалитьОбъявлениеToolStripMenuItem, изменитьОбъявлениеэToolStripMenuItem, списокОбъявленийToolStripMenuItem });
+            объявленияToolStripMenuItem.Name = "объявленияToolStripMenuItem";
+            объявленияToolStripMenuItem.Size = new Size(87, 20);
+            объявленияToolStripMenuItem.Text = "Объявления";
+            // 
+            // создатьОбъявлениеToolStripMenuItem
+            // 
+            создатьОбъявлениеToolStripMenuItem.Name = "создатьОбъявлениеToolStripMenuItem";
+            создатьОбъявлениеToolStripMenuItem.Size = new Size(197, 22);
+            создатьОбъявлениеToolStripMenuItem.Text = "Создать объявление";
+            создатьОбъявлениеToolStripMenuItem.Click += создатьОбъявлениеToolStripMenuItem_Click;
+            // 
+            // удалитьОбъявлениеToolStripMenuItem
+            // 
+            удалитьОбъявлениеToolStripMenuItem.Name = "удалитьОбъявлениеToolStripMenuItem";
+            удалитьОбъявлениеToolStripMenuItem.Size = new Size(197, 22);
+            удалитьОбъявлениеToolStripMenuItem.Text = "Удалить объявление";
+            удалитьОбъявлениеToolStripMenuItem.Click += удалитьОбъявлениеToolStripMenuItem_Click;
+            // 
+            // изменитьОбъявлениеэToolStripMenuItem
+            // 
+            изменитьОбъявлениеэToolStripMenuItem.Name = "изменитьОбъявлениеэToolStripMenuItem";
+            изменитьОбъявлениеэToolStripMenuItem.Size = new Size(197, 22);
+            изменитьОбъявлениеэToolStripMenuItem.Text = "Изменить объявление";
+            изменитьОбъявлениеэToolStripMenuItem.Click += изменитьОбъявлениеэToolStripMenuItem_Click;
+            // 
+            // списокОбъявленийToolStripMenuItem
+            // 
+            списокОбъявленийToolStripMenuItem.Name = "списокОбъявленийToolStripMenuItem";
+            списокОбъявленийToolStripMenuItem.Size = new Size(197, 22);
+            списокОбъявленийToolStripMenuItem.Text = "Список объявлений";
+            списокОбъявленийToolStripMenuItem.Click += списокОбъявленийToolStripMenuItem_Click;
+            // 
+            // категорииToolStripMenuItem
+            // 
+            категорииToolStripMenuItem.DropDownItems.AddRange(new ToolStripItem[] { создатьКатегориюToolStripMenuItem, удалитьКатегориюToolStripMenuItem, изменитьКатегориюToolStripMenuItem, списокКатегорийToolStripMenuItem });
+            категорииToolStripMenuItem.Name = "категорииToolStripMenuItem";
+            категорииToolStripMenuItem.Size = new Size(76, 20);
+            категорииToolStripMenuItem.Text = "Категории";
+            // 
+            // создатьКатегориюToolStripMenuItem
+            // 
+            создатьКатегориюToolStripMenuItem.Name = "создатьКатегориюToolStripMenuItem";
+            создатьКатегориюToolStripMenuItem.Size = new Size(190, 22);
+            создатьКатегориюToolStripMenuItem.Text = "Создать категорию";
+            создатьКатегориюToolStripMenuItem.Click += создатьКатегориюToolStripMenuItem_Click;
+            // 
+            // удалитьКатегориюToolStripMenuItem
+            // 
+            удалитьКатегориюToolStripMenuItem.Name = "удалитьКатегориюToolStripMenuItem";
+            удалитьКатегориюToolStripMenuItem.Size = new Size(190, 22);
+            удалитьКатегориюToolStripMenuItem.Text = "Удалить категорию";
+            удалитьКатегориюToolStripMenuItem.Click += удалитьКатегориюToolStripMenuItem_Click;
+            // 
+            // изменитьКатегориюToolStripMenuItem
+            // 
+            изменитьКатегориюToolStripMenuItem.Name = "изменитьКатегориюToolStripMenuItem";
+            изменитьКатегориюToolStripMenuItem.Size = new Size(190, 22);
+            изменитьКатегориюToolStripMenuItem.Text = "Изменить категорию";
+            изменитьКатегориюToolStripMenuItem.Click += изменитьКатегориюToolStripMenuItem_Click;
+            // 
+            // списокКатегорийToolStripMenuItem
+            // 
+            списокКатегорийToolStripMenuItem.Name = "списокКатегорийToolStripMenuItem";
+            списокКатегорийToolStripMenuItem.Size = new Size(190, 22);
+            списокКатегорийToolStripMenuItem.Text = "Список категорий";
+            списокКатегорийToolStripMenuItem.Click += списокКатегорийToolStripMenuItem_Click;
+            // 
+            // подкатегорииToolStripMenuItem
+            // 
+            подкатегорииToolStripMenuItem.DropDownItems.AddRange(new ToolStripItem[] { создатьПодкатеориюToolStripMenuItem, удалитьПодкатегориюToolStripMenuItem, изменитьПодкатегориюToolStripMenuItem, списокПодкатегоийToolStripMenuItem });
+            подкатегорииToolStripMenuItem.Name = "подкатегорииToolStripMenuItem";
+            подкатегорииToolStripMenuItem.Size = new Size(97, 20);
+            подкатегорииToolStripMenuItem.Text = "Подкатегории";
+            // 
+            // создатьПодкатеориюToolStripMenuItem
+            // 
+            создатьПодкатеориюToolStripMenuItem.Name = "создатьПодкатеориюToolStripMenuItem";
+            создатьПодкатеориюToolStripMenuItem.Size = new Size(210, 22);
+            создатьПодкатеориюToolStripMenuItem.Text = "Создать подкатегорию";
+            создатьПодкатеориюToolStripMenuItem.Click += создатьПодкатеориюToolStripMenuItem_Click;
+            // 
+            // удалитьПодкатегориюToolStripMenuItem
+            // 
+            удалитьПодкатегориюToolStripMenuItem.Name = "удалитьПодкатегориюToolStripMenuItem";
+            удалитьПодкатегориюToolStripMenuItem.Size = new Size(210, 22);
+            удалитьПодкатегориюToolStripMenuItem.Text = "Удалить подкатегорию";
+            удалитьПодкатегориюToolStripMenuItem.Click += удалитьПодкатегориюToolStripMenuItem_Click;
+            // 
+            // изменитьПодкатегориюToolStripMenuItem
+            // 
+            изменитьПодкатегориюToolStripMenuItem.Name = "изменитьПодкатегориюToolStripMenuItem";
+            изменитьПодкатегориюToolStripMenuItem.Size = new Size(210, 22);
+            изменитьПодкатегориюToolStripMenuItem.Text = "Изменить подкатегорию";
+            изменитьПодкатегориюToolStripMenuItem.Click += изменитьПодкатегориюToolStripMenuItem_Click;
+            // 
+            // списокПодкатегоийToolStripMenuItem
+            // 
+            списокПодкатегоийToolStripMenuItem.Name = "списокПодкатегоийToolStripMenuItem";
+            списокПодкатегоийToolStripMenuItem.Size = new Size(210, 22);
+            списокПодкатегоийToolStripMenuItem.Text = "Список подкатегорий";
+            списокПодкатегоийToolStripMenuItem.Click += списокПодкатегоийToolStripMenuItem_Click;
+            // 
+            // toolStripMenuItem1
+            // 
+            toolStripMenuItem1.DropDownItems.AddRange(new ToolStripItem[] { toolStripMenuItem2, toolStripMenuItem3, toolStripMenuItem4, toolStripMenuItem5 });
+            toolStripMenuItem1.Name = "toolStripMenuItem1";
+            toolStripMenuItem1.Size = new Size(67, 20);
+            toolStripMenuItem1.Text = "Регионы";
+            // 
+            // toolStripMenuItem2
+            // 
+            toolStripMenuItem2.Name = "toolStripMenuItem2";
+            toolStripMenuItem2.Size = new Size(180, 22);
+            toolStripMenuItem2.Text = "Создать регион";
+            toolStripMenuItem2.Click += создатьРегионToolStripMenuItem_Click;
+            // 
+            // toolStripMenuItem3
+            // 
+            toolStripMenuItem3.Name = "toolStripMenuItem3";
+            toolStripMenuItem3.Size = new Size(180, 22);
+            toolStripMenuItem3.Text = "Удалить регион";
+            toolStripMenuItem3.Click += удалитьРегионToolStripMenuItem_Click;
+            // 
+            // toolStripMenuItem4
+            // 
+            toolStripMenuItem4.Name = "toolStripMenuItem4";
+            toolStripMenuItem4.Size = new Size(180, 22);
+            toolStripMenuItem4.Text = "Изменить регион";
+            toolStripMenuItem4.Click += изменитьРегионToolStripMenuItem_Click;
+            // 
+            // toolStripMenuItem5
+            // 
+            toolStripMenuItem5.Name = "toolStripMenuItem5";
+            toolStripMenuItem5.Size = new Size(180, 22);
+            toolStripMenuItem5.Text = "Список регион";
+            toolStripMenuItem5.Click += списокРегионToolStripMenuItem_Click;
+            // 
+            // label1
+            // 
+            label1.AutoSize = true;
+            label1.Location = new Point(3, 11);
+            label1.Name = "label1";
+            label1.Size = new Size(225, 15);
+            label1.TabIndex = 1;
+            label1.Text = "Сценарий 1: Добавление 1000 клиентов";
+            // 
+            // button1
+            // 
+            button1.Location = new Point(63, 66);
+            button1.Name = "button1";
+            button1.Size = new Size(95, 33);
+            button1.TabIndex = 2;
+            button1.Text = "Старт";
+            button1.UseVisualStyleBackColor = true;
+            button1.Click += button1_Click;
+            // 
+            // panel1
+            // 
+            panel1.Controls.Add(button1);
+            panel1.Controls.Add(label1);
+            panel1.Location = new Point(12, 83);
+            panel1.Name = "panel1";
+            panel1.Size = new Size(222, 102);
+            panel1.TabIndex = 3;
+            // 
+            // panel2
+            // 
+            panel2.Controls.Add(button2);
+            panel2.Controls.Add(label2);
+            panel2.Location = new Point(240, 83);
+            panel2.Name = "panel2";
+            panel2.Size = new Size(222, 102);
+            panel2.TabIndex = 4;
+            // 
+            // button2
+            // 
+            button2.Location = new Point(63, 66);
+            button2.Name = "button2";
+            button2.Size = new Size(95, 33);
+            button2.TabIndex = 2;
+            button2.Text = "Старт";
+            button2.UseVisualStyleBackColor = true;
+            button2.Click += button2_Click;
+            // 
+            // label2
+            // 
+            label2.AutoSize = true;
+            label2.Location = new Point(3, 11);
+            label2.Name = "label2";
+            label2.Size = new Size(210, 15);
+            label2.TabIndex = 1;
+            label2.Text = "Сценарий 2: Удаление 1000 клиентов";
+            // 
+            // panel3
+            // 
+            panel3.Controls.Add(button3);
+            panel3.Controls.Add(label3);
+            panel3.Location = new Point(468, 83);
+            panel3.Name = "panel3";
+            panel3.Size = new Size(222, 102);
+            panel3.TabIndex = 5;
+            // 
+            // button3
+            // 
+            button3.Location = new Point(63, 66);
+            button3.Name = "button3";
+            button3.Size = new Size(95, 33);
+            button3.TabIndex = 2;
+            button3.Text = "Старт";
+            button3.UseVisualStyleBackColor = true;
+            button3.Click += button3_Click;
+            // 
+            // label3
+            // 
+            label3.Location = new Point(7, 11);
+            label3.Name = "label3";
+            label3.Size = new Size(213, 44);
+            label3.TabIndex = 1;
+            label3.Text = "Сценарий 3: Изменение фамилий 1000 клиентов на \"surname2\"";
+            // 
+            // toolStripMenuItem6
+            // 
+            toolStripMenuItem6.DropDownItems.AddRange(new ToolStripItem[] { toolStripMenuItem7, toolStripMenuItem8, toolStripMenuItem9, toolStripMenuItem10 });
+            toolStripMenuItem6.Name = "toolStripMenuItem6";
+            toolStripMenuItem6.Size = new Size(58, 20);
+            toolStripMenuItem6.Text = "Города";
+            // 
+            // toolStripMenuItem7
+            // 
+            toolStripMenuItem7.Name = "toolStripMenuItem7";
+            toolStripMenuItem7.Size = new Size(180, 22);
+            toolStripMenuItem7.Text = "Создать город";
+            toolStripMenuItem7.Click += создатьГородToolStripMenuItem_Click;
+            // 
+            // toolStripMenuItem8
+            // 
+            toolStripMenuItem8.Name = "toolStripMenuItem8";
+            toolStripMenuItem8.Size = new Size(180, 22);
+            toolStripMenuItem8.Text = "Удалить город";
+            toolStripMenuItem8.Click += удалитьГородToolStripMenuItem_Click;
+            // 
+            // toolStripMenuItem9
+            // 
+            toolStripMenuItem9.Name = "toolStripMenuItem9";
+            toolStripMenuItem9.Size = new Size(180, 22);
+            toolStripMenuItem9.Text = "Изменить город";
+            toolStripMenuItem9.Click += изменитьГородToolStripMenuItem_Click;
+            // 
+            // toolStripMenuItem10
+            // 
+            toolStripMenuItem10.Name = "toolStripMenuItem10";
+            toolStripMenuItem10.Size = new Size(180, 22);
+            toolStripMenuItem10.Text = "Список город";
+            toolStripMenuItem10.Click += списокГородToolStripMenuItem_Click;
+            // 
+            // MainForm
+            // 
+            AutoScaleDimensions = new SizeF(7F, 15F);
+            AutoScaleMode = AutoScaleMode.Font;
+            ClientSize = new Size(700, 338);
+            Controls.Add(panel3);
+            Controls.Add(panel2);
+            Controls.Add(panel1);
+            Controls.Add(menuStrip1);
+            MainMenuStrip = menuStrip1;
+            Margin = new Padding(3, 2, 3, 2);
+            Name = "MainForm";
+            Text = "MainForm";
+            menuStrip1.ResumeLayout(false);
+            menuStrip1.PerformLayout();
+            panel1.ResumeLayout(false);
+            panel1.PerformLayout();
+            panel2.ResumeLayout(false);
+            panel2.PerformLayout();
+            panel3.ResumeLayout(false);
+            ResumeLayout(false);
+            PerformLayout();
+        }
+
+        #endregion
+
+        private MenuStrip menuStrip1;
+        private ToolStripMenuItem клиентыToolStripMenuItem;
+        private ToolStripMenuItem создатьКлиентаToolStripMenuItem;
+        private ToolStripMenuItem удалитьКлиентаToolStripMenuItem;
+        private ToolStripMenuItem изменитьДанныеКлиентаToolStripMenuItem;
+        private ToolStripMenuItem списокКлиентвToolStripMenuItem;
+        private ToolStripMenuItem объявленияToolStripMenuItem;
+        private ToolStripMenuItem создатьОбъявлениеToolStripMenuItem;
+        private ToolStripMenuItem категорииToolStripMenuItem;
+        private ToolStripMenuItem подкатегорииToolStripMenuItem;
+        private ToolStripMenuItem удалитьОбъявлениеToolStripMenuItem;
+        private ToolStripMenuItem изменитьОбъявлениеэToolStripMenuItem;
+        private ToolStripMenuItem списокОбъявленийToolStripMenuItem;
+        private ToolStripMenuItem создатьКатегориюToolStripMenuItem;
+        private ToolStripMenuItem удалитьКатегориюToolStripMenuItem;
+        private ToolStripMenuItem изменитьКатегориюToolStripMenuItem;
+        private ToolStripMenuItem списокКатегорийToolStripMenuItem;
+        private ToolStripMenuItem создатьПодкатеориюToolStripMenuItem;
+        private ToolStripMenuItem удалитьПодкатегориюToolStripMenuItem;
+        private ToolStripMenuItem изменитьПодкатегориюToolStripMenuItem;
+        private ToolStripMenuItem списокПодкатегоийToolStripMenuItem;
+        private Label label1;
+        private Button button1;
+        private Panel panel1;
+        private Panel panel2;
+        private Button button2;
+        private Label label2;
+        private Panel panel3;
+        private Button button3;
+        private Label label3;
+        private ToolStripMenuItem toolStripMenuItem1;
+        private ToolStripMenuItem toolStripMenuItem2;
+        private ToolStripMenuItem toolStripMenuItem3;
+        private ToolStripMenuItem toolStripMenuItem4;
+        private ToolStripMenuItem toolStripMenuItem5;
+        private ToolStripMenuItem toolStripMenuItem6;
+        private ToolStripMenuItem toolStripMenuItem7;
+        private ToolStripMenuItem toolStripMenuItem8;
+        private ToolStripMenuItem toolStripMenuItem9;
+        private ToolStripMenuItem toolStripMenuItem10;
+    }
+}

BulletinBoard/BulletinBoard/MainForm.cs

@@ -0,0 +1,205 @@
+using System;
+using System.Collections.Generic;
+using System.ComponentModel;
+using System.Data;
+using System.Drawing;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using System.Windows.Forms;
+
+namespace WebsiteForPlacingAds
+{
+    public partial class MainForm : Form
+    {
+        AbstractManagmentDatabase managmentDatabase;
+        
+
+        public MainForm()
+        {
+            InitializeComponent();
+            managmentDatabase = new ManagmentDatabase("Server=192.168.56.101;Port=5432;User Id=postgres;Password=postgres;Database=lab4;");
+        }
+
+        private void создатьКатегориюToolStripMenuItem_Click(object sender, EventArgs e)
+        {
+            CreateCategoriesForm ccf = new CreateCategoriesForm(managmentDatabase);
+            ccf.Show();
+        }
+
+        private void удалитьКатегориюToolStripMenuItem_Click(object sender, EventArgs e)
+        {
+            DeleteCategoriesForm dcf = new DeleteCategoriesForm(managmentDatabase);
+            dcf.Show();
+        }
+
+        private void изменитьКатегориюToolStripMenuItem_Click(object sender, EventArgs e)
+        {
+            UpdateCategoriesForm ucf = new UpdateCategoriesForm(managmentDatabase);
+            ucf.Show();
+        }
+
+        private void списокКатегорийToolStripMenuItem_Click(object sender, EventArgs e)
+        {
+            ListCategoriesForm lcf = new ListCategoriesForm(managmentDatabase);
+            lcf.Show();
+        }
+
+        private void создатьРегионToolStripMenuItem_Click(object sender, EventArgs e)
+        {
+            CreateRegionsForm crf = new CreateRegionsForm(managmentDatabase);
+            crf.Show();
+        }
+
+        private void удалитьРегионToolStripMenuItem_Click(object sender, EventArgs e)
+        {
+            DeleteRegionsForm drf = new DeleteRegionsForm(managmentDatabase);
+            drf.Show();
+        }
+
+        private void изменитьРегионToolStripMenuItem_Click(object sender, EventArgs e)
+        {
+            UpdateRegionsForm urf = new UpdateRegionsForm(managmentDatabase);
+            urf.Show();
+        }
+
+        private void списокРегионToolStripMenuItem_Click(object sender, EventArgs e)
+        {
+            ListRegionsForm lrf = new ListRegionsForm(managmentDatabase);
+            lrf.Show();
+        }
+
+        private void создатьГородToolStripMenuItem_Click(object sender, EventArgs e)
+        {
+            CreateCitiesForm crf = new CreateCitiesForm(managmentDatabase);
+            crf.Show();
+        }
+
+        private void удалитьГородToolStripMenuItem_Click(object sender, EventArgs e)
+        {
+            DeleteCitiesForm drf = new DeleteCitiesForm(managmentDatabase);
+            drf.Show();
+        }
+
+        private void изменитьГородToolStripMenuItem_Click(object sender, EventArgs e)
+        {
+            UpdateCitiesForm urf = new UpdateCitiesForm(managmentDatabase);
+            urf.Show();
+        }
+
+        private void списокГородToolStripMenuItem_Click(object sender, EventArgs e)
+        {
+            ListCitiesForm lrf = new ListCitiesForm(managmentDatabase);
+            lrf.Show();
+        }
+
+        private void создатьОбъявлениеToolStripMenuItem_Click(object sender, EventArgs e)
+        {
+            CreateAdsForm caf = new CreateAdsForm(managmentDatabase);
+            caf.Show();
+        }
+
+        private void удалитьОбъявлениеToolStripMenuItem_Click(object sender, EventArgs e)
+        {
+            DeleteAdsForm uaf = new DeleteAdsForm(managmentDatabase);
+            uaf.Show();
+        }
+
+        private void изменитьОбъявлениеэToolStripMenuItem_Click(object sender, EventArgs e)
+        {
+            UpdateAdsForm daf = new UpdateAdsForm(managmentDatabase);
+            daf.Show();
+        }
+
+        private void списокОбъявленийToolStripMenuItem_Click(object sender, EventArgs e)
+        {
+            ListAdsForm laf = new ListAdsForm(managmentDatabase);
+            laf.Show();
+        }
+
+        private void создатьКлиентаToolStripMenuItem_Click(object sender, EventArgs e)
+        {
+            CreateClientsForm ccf = new CreateClientsForm(managmentDatabase);
+            ccf.Show();
+        }
+
+        private void удалитьКлиентаToolStripMenuItem_Click(object sender, EventArgs e)
+        {
+            DeleteClientsForm dcf = new DeleteClientsForm(managmentDatabase);
+            dcf.Show();
+        }
+
+        private void изменитьДанныеКлиентаToolStripMenuItem_Click(object sender, EventArgs e)
+        {
+            UpdateClientsForm ucf = new UpdateClientsForm(managmentDatabase);
+            ucf.Show();
+        }
+        private void списокКлиентвToolStripMenuItem_Click(object sender, EventArgs e)
+        {
+            ListClientsForm lcf = new ListClientsForm(managmentDatabase);
+            lcf.Show();
+        }
+
+        private void создатьПодкатеориюToolStripMenuItem_Click(object sender, EventArgs e)
+        {
+            CreateSubcategoriesForm csf = new CreateSubcategoriesForm(managmentDatabase);
+            csf.Show();
+        }
+
+        private void удалитьПодкатегориюToolStripMenuItem_Click(object sender, EventArgs e)
+        {
+            DeleteSubcategoriesForm dsf = new DeleteSubcategoriesForm(managmentDatabase);
+            dsf.Show();
+        }
+
+        private void изменитьПодкатегориюToolStripMenuItem_Click(object sender, EventArgs e)
+        {
+            UpdateSubcategoriesForm usf = new UpdateSubcategoriesForm(managmentDatabase);
+            usf.Show();
+        }
+
+        private void списокПодкатегоийToolStripMenuItem_Click(object sender, EventArgs e)
+        {
+            ListSubcategoriesForm lsf = new ListSubcategoriesForm(managmentDatabase);
+            lsf.Show();
+        }
+        private void button1_Click(object sender, EventArgs e)
+        {
+            DateTime start = DateTime.Now;
+
+            for (int i = 0; i < 1000; i++)
+            {
+                managmentDatabase.insertInto("clients", "'name'", "'surname'", "'patronymic'", "'email@mail.ru'", $"{89372511129}", "'20.01.2022'");
+            }
+
+            DateTime end = DateTime.Now;
+            TimeSpan duration = end - start;
+            MessageBox.Show($"Сценарий 1 завершен! Время выполнения: {duration.TotalMilliseconds} мс");
+        }
+
+        private void button2_Click(object sender, EventArgs e)
+        {
+            DateTime start = DateTime.Now;
+
+            for (int i = 0; i < 1000; i++)
+            {
+                managmentDatabase.deleteEntry("clients", "name");
+            }
+
+            DateTime end = DateTime.Now;
+            TimeSpan duration = end - start;
+            MessageBox.Show($"Сценарий 2 завершен! Время выполнения: {duration.TotalMilliseconds} мс");
+        }
+
+        private void button3_Click(object sender, EventArgs e)
+        {
+            DateTime start = DateTime.Now;
+
+            managmentDatabase.ExecuteNonQuery("Update clients Set surname = 'surname2' where surname = 'surname'");
+
+            DateTime end = DateTime.Now;
+            TimeSpan duration = end - start;
+            MessageBox.Show($"Сценарий 3 завершен! Время выполнения: {duration.TotalMilliseconds} мс");
+        }
+    }
+}

BulletinBoard/BulletinBoard/MainForm.resx

@@ -0,0 +1,123 @@
+<?xml version="1.0" encoding="utf-8"?>
+<root>
+  <!--
+    Microsoft ResX Schema 
+
+    Version 2.0
+
+    The primary goals of this format is to allow a simple XML format
+    that is mostly human readable. The generation and parsing of the
+    various data types are done through the TypeConverter classes
+    associated with the data types.
+
+    Example:
+
+    ... ado.net/XML headers & schema ...
+    <resheader name="resmimetype">text/microsoft-resx</resheader>
+    <resheader name="version">2.0</resheader>
+    <resheader name="reader">System.Resources.ResXResourceReader, System.Windows.Forms, ...</resheader>
+    <resheader name="writer">System.Resources.ResXResourceWriter, System.Windows.Forms, ...</resheader>
+    <data name="Name1"><value>this is my long string</value><comment>this is a comment</comment></data>
+    <data name="Color1" type="System.Drawing.Color, System.Drawing">Blue</data>
+    <data name="Bitmap1" mimetype="application/x-microsoft.net.object.binary.base64">
+        <value>[base64 mime encoded serialized .NET Framework object]</value>
+    </data>
+    <data name="Icon1" type="System.Drawing.Icon, System.Drawing" mimetype="application/x-microsoft.net.object.bytearray.base64">
+        <value>[base64 mime encoded string representing a byte array form of the .NET Framework object]</value>
+        <comment>This is a comment</comment>
+    </data>
+
+    There are any number of "resheader" rows that contain simple
+    name/value pairs.
+
+    Each data row contains a name, and value. The row also contains a
+    type or mimetype. Type corresponds to a .NET class that support
+    text/value conversion through the TypeConverter architecture.
+    Classes that don't support this are serialized and stored with the
+    mimetype set.
+
+    The mimetype is used for serialized objects, and tells the
+    ResXResourceReader how to depersist the object. This is currently not
+    extensible. For a given mimetype the value must be set accordingly:
+
+    Note - application/x-microsoft.net.object.binary.base64 is the format
+    that the ResXResourceWriter will generate, however the reader can
+    read any of the formats listed below.
+
+    mimetype: application/x-microsoft.net.object.binary.base64
+    value   : The object must be serialized with
+            : System.Runtime.Serialization.Formatters.Binary.BinaryFormatter
+            : and then encoded with base64 encoding.
+    
+    mimetype: application/x-microsoft.net.object.soap.base64
+    value   : The object must be serialized with
+            : System.Runtime.Serialization.Formatters.Soap.SoapFormatter
+            : and then encoded with base64 encoding.
+
+    mimetype: application/x-microsoft.net.object.bytearray.base64
+    value   : The object must be serialized into a byte array
+            : using a System.ComponentModel.TypeConverter
+            : and then encoded with base64 encoding.
+    -->
+  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
+    <xsd:import namespace="http://www.w3.org/XML/1998/namespace" />
+    <xsd:element name="root" msdata:IsDataSet="true">
+      <xsd:complexType>
+        <xsd:choice maxOccurs="unbounded">
+          <xsd:element name="metadata">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" />
+              </xsd:sequence>
+              <xsd:attribute name="name" use="required" type="xsd:string" />
+              <xsd:attribute name="type" type="xsd:string" />
+              <xsd:attribute name="mimetype" type="xsd:string" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="assembly">
+            <xsd:complexType>
+              <xsd:attribute name="alias" type="xsd:string" />
+              <xsd:attribute name="name" type="xsd:string" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="data">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" msdata:Ordinal="1" />
+              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />
+              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="resheader">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" />
+            </xsd:complexType>
+          </xsd:element>
+        </xsd:choice>
+      </xsd:complexType>
+    </xsd:element>
+  </xsd:schema>
+  <resheader name="resmimetype">
+    <value>text/microsoft-resx</value>
+  </resheader>
+  <resheader name="version">
+    <value>2.0</value>
+  </resheader>
+  <resheader name="reader">
+    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+  <resheader name="writer">
+    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+  <metadata name="menuStrip1.TrayLocation" type="System.Drawing.Point, System.Drawing, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a">
+    <value>17, 17</value>
+  </metadata>
+</root>

BulletinBoard/BulletinBoard/ManagmentDatabase.cs

@@ -0,0 +1,85 @@
+using Npgsql;
+using System;
+using System.Collections.Generic;
+using System.Data;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace WebsiteForPlacingAds
+{
+    public class ManagmentDatabase : AbstractManagmentDatabase
+    {
+        protected NpgsqlConnection connection;
+        
+        public ManagmentDatabase(String connectionString)
+        {
+            connection = new NpgsqlConnection(connectionString);
+        }
+        
+        public override Object getRowTableById(string tableName, string columnName, int id)
+        {
+            return ExecuteQuery($"SELECT {columnName} FROM {tableName} WHERE {tableName}_id = {id}").Rows[0][$"{columnName}"];
+        }
+       
+        public override Object getRowTableById(DataTable table, string columnName, int i)
+        {
+            return table.Rows[i][columnName];
+        }
+        
+        public override DataTable getEntryById(string tableName, int id)
+        {
+            return ExecuteQuery($"SELECT * FROM {tableName} WHERE {tableName}_id = {id}");
+        }
+        
+        public override DataTable getAllEntry(string tableName)
+        {
+            return ExecuteQuery($"SELECT * FROM {tableName}");
+        }
+        
+        public override void insertInto(string tableName, params string[] values)
+        {
+            string query = $"INSERT INTO {tableName} VALUES (nextval('seq_{tableName.ToLower()}'), ";       // seq_{tableName.}
+            for (int i = 0; i < values.Length; i++)
+            {
+                if (i < values.Length - 1) query += $"{values[i]}, ";
+                else query += $"{values[i]})";
+            }
+            ExecuteNonQuery(query);
+        }
+       
+        public override void deleteEntry(string tableName, int id)
+        {
+            ExecuteNonQuery($"DELETE FROM {tableName} WHERE {tableName}_id = {id}");
+        }
+        
+        public override void deleteEntry(string tableName, string name)
+        {
+            ExecuteNonQuery($"DELETE FROM {tableName} WHERE name = '{name}'");
+        }
+        
+        public override void reduceSeq(string seq, int currval)
+        {
+            ExecuteNonQuery($"SELECT setval('{seq}', {currval});");
+        }
+        
+        public override void ExecuteNonQuery(string query)
+        {
+            connection.Open();
+            NpgsqlCommand command = new NpgsqlCommand(query, connection);
+            command.ExecuteNonQuery();
+            connection.Close();
+        }
+        
+        public override DataTable ExecuteQuery(string query)
+        {
+            connection.Open();
+            NpgsqlCommand command = new NpgsqlCommand(query, connection);
+            NpgsqlDataAdapter adapter = new NpgsqlDataAdapter(command);
+            DataTable result = new DataTable();
+            adapter.Fill(result);
+            connection.Close();
+            return result;
+        }
+    }
+}

BulletinBoard/BulletinBoard/Program.cs

@@ -0,0 +1,17 @@
+namespace WebsiteForPlacingAds
+{
+    internal static class Program
+    {
+        /// <summary>
+        ///  The main entry point for the application.
+        /// </summary>
+        [STAThread]
+        static void Main()
+        {
+            // To customize application configuration such as set high DPI settings or default font,
+            // see https://aka.ms/applicationconfiguration.
+            ApplicationConfiguration.Initialize();
+            Application.Run(new MainForm());
+        }
+    }
+}

BulletinBoard/BulletinBoard/RegionsForm/CreateRegionsForm.Designer.cs

@@ -0,0 +1,82 @@
+namespace WebsiteForPlacingAds
+{
+    partial class CreateRegionsForm
+    {
+        /// <summary>
+        ///  Required designer variable.
+        /// </summary>
+        private System.ComponentModel.IContainer components = null;
+
+        /// <summary>
+        ///  Clean up any resources being used.
+        /// </summary>
+        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
+        protected override void Dispose(bool disposing)
+        {
+            if (disposing && (components != null))
+            {
+                components.Dispose();
+            }
+            base.Dispose(disposing);
+        }
+
+        #region Windows Form Designer generated code
+
+        /// <summary>
+        ///  Required method for Designer support - do not modify
+        ///  the contents of this method with the code editor.
+        /// </summary>
+        private void InitializeComponent()
+        {
+            buttonCreateCity = new Button();
+            labelName = new Label();
+            textBoxName = new TextBox();
+            SuspendLayout();
+            // 
+            // buttonCreateCity
+            // 
+            buttonCreateCity.Location = new Point(49, 93);
+            buttonCreateCity.Name = "buttonCreateCity";
+            buttonCreateCity.Size = new Size(273, 39);
+            buttonCreateCity.TabIndex = 0;
+            buttonCreateCity.Text = "Добавить город";
+            buttonCreateCity.UseVisualStyleBackColor = true;
+            buttonCreateCity.Click += buttonCreateCity_Click;
+            // 
+            // labelName
+            // 
+            labelName.AutoSize = true;
+            labelName.Location = new Point(49, 11);
+            labelName.Name = "labelName";
+            labelName.Size = new Size(77, 20);
+            labelName.TabIndex = 1;
+            labelName.Text = "Название";
+            // 
+            // textBoxName
+            // 
+            textBoxName.Location = new Point(49, 35);
+            textBoxName.Name = "textBoxName";
+            textBoxName.Size = new Size(273, 27);
+            textBoxName.TabIndex = 2;
+            // 
+            // CreateRegionsForm
+            // 
+            AutoScaleDimensions = new SizeF(8F, 20F);
+            AutoScaleMode = AutoScaleMode.Font;
+            ClientSize = new Size(370, 157);
+            Controls.Add(textBoxName);
+            Controls.Add(labelName);
+            Controls.Add(buttonCreateCity);
+            Name = "CreateRegionsForm";
+            Text = "Добавить Город";
+            ResumeLayout(false);
+            PerformLayout();
+        }
+
+        #endregion
+
+        private Button buttonCreateCity;
+        private Label labelName;
+        private TextBox textBoxName;
+    }
+}

BulletinBoard/BulletinBoard/RegionsForm/CreateRegionsForm.cs

@@ -0,0 +1,40 @@
+using System.Data;
+
+namespace WebsiteForPlacingAds
+{
+    public partial class CreateRegionsForm : Form
+    {
+        AbstractManagmentDatabase managmentDatabase;
+        public CreateRegionsForm(AbstractManagmentDatabase managmentDatabase)
+        {
+            InitializeComponent();
+            this.managmentDatabase = managmentDatabase;
+        }
+
+        private void buttonCreateCity_Click(object sender, EventArgs e)
+        {
+            string name = textBoxName.Text;
+
+
+            try
+            {
+                DateTime start = DateTime.Now;
+
+                managmentDatabase.insertInto("regions", $"'{name}'");
+                MessageBox.Show("Äîáàâëåíî!");
+
+                DateTime end = DateTime.Now;
+                TimeSpan duration = end - start;
+                MessageBox.Show($"Äîáàâëåíî! Âðåìÿ âûïîëíåíèÿ: {duration.TotalMilliseconds} ìñ");
+
+                // Çàêðûòü òåêóùóþ ôîðìó ïîñëå âûïîëíåíèÿ äåéñòâèé
+                this.Close();
+            }
+            catch (Exception ex)
+            {
+                MessageBox.Show("Íå óäàëîñü äîáàâèòü");
+            }
+        }
+
+    }
+}

BulletinBoard/BulletinBoard/RegionsForm/CreateRegionsForm.resx

@@ -0,0 +1,120 @@
+<?xml version="1.0" encoding="utf-8"?>
+<root>
+  <!--
+    Microsoft ResX Schema 
+
+    Version 2.0
+
+    The primary goals of this format is to allow a simple XML format
+    that is mostly human readable. The generation and parsing of the
+    various data types are done through the TypeConverter classes
+    associated with the data types.
+
+    Example:
+
+    ... ado.net/XML headers & schema ...
+    <resheader name="resmimetype">text/microsoft-resx</resheader>
+    <resheader name="version">2.0</resheader>
+    <resheader name="reader">System.Resources.ResXResourceReader, System.Windows.Forms, ...</resheader>
+    <resheader name="writer">System.Resources.ResXResourceWriter, System.Windows.Forms, ...</resheader>
+    <data name="Name1"><value>this is my long string</value><comment>this is a comment</comment></data>
+    <data name="Color1" type="System.Drawing.Color, System.Drawing">Blue</data>
+    <data name="Bitmap1" mimetype="application/x-microsoft.net.object.binary.base64">
+        <value>[base64 mime encoded serialized .NET Framework object]</value>
+    </data>
+    <data name="Icon1" type="System.Drawing.Icon, System.Drawing" mimetype="application/x-microsoft.net.object.bytearray.base64">
+        <value>[base64 mime encoded string representing a byte array form of the .NET Framework object]</value>
+        <comment>This is a comment</comment>
+    </data>
+
+    There are any number of "resheader" rows that contain simple
+    name/value pairs.
+
+    Each data row contains a name, and value. The row also contains a
+    type or mimetype. Type corresponds to a .NET class that support
+    text/value conversion through the TypeConverter architecture.
+    Classes that don't support this are serialized and stored with the
+    mimetype set.
+
+    The mimetype is used for serialized objects, and tells the
+    ResXResourceReader how to depersist the object. This is currently not
+    extensible. For a given mimetype the value must be set accordingly:
+
+    Note - application/x-microsoft.net.object.binary.base64 is the format
+    that the ResXResourceWriter will generate, however the reader can
+    read any of the formats listed below.
+
+    mimetype: application/x-microsoft.net.object.binary.base64
+    value   : The object must be serialized with
+            : System.Runtime.Serialization.Formatters.Binary.BinaryFormatter
+            : and then encoded with base64 encoding.
+    
+    mimetype: application/x-microsoft.net.object.soap.base64
+    value   : The object must be serialized with
+            : System.Runtime.Serialization.Formatters.Soap.SoapFormatter
+            : and then encoded with base64 encoding.
+
+    mimetype: application/x-microsoft.net.object.bytearray.base64
+    value   : The object must be serialized into a byte array
+            : using a System.ComponentModel.TypeConverter
+            : and then encoded with base64 encoding.
+    -->
+  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
+    <xsd:import namespace="http://www.w3.org/XML/1998/namespace" />
+    <xsd:element name="root" msdata:IsDataSet="true">
+      <xsd:complexType>
+        <xsd:choice maxOccurs="unbounded">
+          <xsd:element name="metadata">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" />
+              </xsd:sequence>
+              <xsd:attribute name="name" use="required" type="xsd:string" />
+              <xsd:attribute name="type" type="xsd:string" />
+              <xsd:attribute name="mimetype" type="xsd:string" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="assembly">
+            <xsd:complexType>
+              <xsd:attribute name="alias" type="xsd:string" />
+              <xsd:attribute name="name" type="xsd:string" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="data">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" msdata:Ordinal="1" />
+              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />
+              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="resheader">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" />
+            </xsd:complexType>
+          </xsd:element>
+        </xsd:choice>
+      </xsd:complexType>
+    </xsd:element>
+  </xsd:schema>
+  <resheader name="resmimetype">
+    <value>text/microsoft-resx</value>
+  </resheader>
+  <resheader name="version">
+    <value>2.0</value>
+  </resheader>
+  <resheader name="reader">
+    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+  <resheader name="writer">
+    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+</root>

BulletinBoard/BulletinBoard/RegionsForm/DeleteRegionsForm.Designer.cs

@@ -0,0 +1,86 @@
+namespace WebsiteForPlacingAds
+{
+    partial class DeleteRegionsForm
+    {
+        /// <summary>
+        /// Required designer variable.
+        /// </summary>
+        private System.ComponentModel.IContainer components = null;
+
+        /// <summary>
+        /// Clean up any resources being used.
+        /// </summary>
+        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
+        protected override void Dispose(bool disposing)
+        {
+            if (disposing && (components != null))
+            {
+                components.Dispose();
+            }
+            base.Dispose(disposing);
+        }
+
+        #region Windows Form Designer generated code
+
+        /// <summary>
+        /// Required method for Designer support - do not modify
+        /// the contents of this method with the code editor.
+        /// </summary>
+        private void InitializeComponent()
+        {
+            label1 = new Label();
+            buttonDeleteRegion = new Button();
+            comboBoxDeleteRegions = new ComboBox();
+            SuspendLayout();
+            // 
+            // label1
+            // 
+            label1.AutoSize = true;
+            label1.Location = new Point(70, 16);
+            label1.Name = "label1";
+            label1.Size = new Size(242, 15);
+            label1.TabIndex = 0;
+            label1.Text = "Выберите регион, которую хотите удалить";
+            // 
+            // buttonDeleteRegion
+            // 
+            buttonDeleteRegion.Location = new Point(132, 85);
+            buttonDeleteRegion.Margin = new Padding(3, 2, 3, 2);
+            buttonDeleteRegion.Name = "buttonDeleteRegion";
+            buttonDeleteRegion.Size = new Size(163, 28);
+            buttonDeleteRegion.TabIndex = 1;
+            buttonDeleteRegion.Text = "Удалить";
+            buttonDeleteRegion.UseVisualStyleBackColor = true;
+            buttonDeleteRegion.Click += buttonDeleteRegion_Click;
+            // 
+            // comboBoxDeleteRegions
+            // 
+            comboBoxDeleteRegions.FormattingEnabled = true;
+            comboBoxDeleteRegions.Location = new Point(35, 48);
+            comboBoxDeleteRegions.Margin = new Padding(3, 2, 3, 2);
+            comboBoxDeleteRegions.Name = "comboBoxDeleteRegions";
+            comboBoxDeleteRegions.Size = new Size(367, 23);
+            comboBoxDeleteRegions.TabIndex = 2;
+            // 
+            // DeleteRegionsForm
+            // 
+            AutoScaleDimensions = new SizeF(7F, 15F);
+            AutoScaleMode = AutoScaleMode.Font;
+            ClientSize = new Size(442, 131);
+            Controls.Add(comboBoxDeleteRegions);
+            Controls.Add(buttonDeleteRegion);
+            Controls.Add(label1);
+            Margin = new Padding(3, 2, 3, 2);
+            Name = "DeleteRegionsForm";
+            Text = "Удалить регион";
+            ResumeLayout(false);
+            PerformLayout();
+        }
+
+        #endregion
+
+        private Label label1;
+        private Button buttonDeleteRegion;
+        private ComboBox comboBoxDeleteRegions;
+    }
+}

BulletinBoard/BulletinBoard/RegionsForm/DeleteRegionsForm.cs

@@ -0,0 +1,61 @@
+using System;
+using System.Collections.Generic;
+using System.ComponentModel;
+using System.Data;
+using System.Drawing;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using System.Windows.Forms;
+
+namespace WebsiteForPlacingAds
+{
+    public partial class DeleteRegionsForm : Form
+    {
+        AbstractManagmentDatabase managmentDatabase;
+        private int setval_seq;
+        public DeleteRegionsForm(AbstractManagmentDatabase managmentDatabase)
+        {
+            InitializeComponent();
+            this.managmentDatabase = managmentDatabase;
+            LoadData();
+        }
+
+        private void buttonDeleteRegion_Click(object sender, EventArgs e)
+        {
+            string[] categories = comboBoxDeleteRegions.SelectedItem.ToString().Split("|");
+            string category_id = categories[0].Trim();
+            try
+            {
+                DateTime start = DateTime.Now;
+
+                managmentDatabase.deleteEntry("regions", int.Parse(category_id));
+                LoadData();
+                if (setval_seq > 0) managmentDatabase.reduceSeq("seq_regions", setval_seq);
+                MessageBox.Show("Удалено!");
+
+                DateTime end = DateTime.Now;
+                TimeSpan duration = end - start;
+                MessageBox.Show($"Добавлено! Время выполнения: {duration.TotalMilliseconds} мс");
+            }
+            catch (Exception ex)
+            {
+                MessageBox.Show("Не удалось удалить");
+            }
+        }
+        public void LoadData()
+        {
+            comboBoxDeleteRegions.Items.Clear();
+            DataTable result = managmentDatabase.getAllEntry("Regions");
+            setval_seq = result.Rows.Count;
+            string Regions = "";
+            for (int i = 0; i < result.Rows.Count; i++)
+            {
+                setval_seq = Math.Max(Convert.ToInt32(managmentDatabase.getRowTableById(result, "regions_id", i)), setval_seq);
+                Regions = managmentDatabase.getRowTableById(result, "regions_id", i).ToString() + " | " +
+                                managmentDatabase.getRowTableById(result, "name", i).ToString()  + "\n";
+                comboBoxDeleteRegions.Items.Add(Regions);
+            }
+        }
+    }
+}

BulletinBoard/BulletinBoard/RegionsForm/DeleteRegionsForm.resx

@@ -0,0 +1,120 @@
+<?xml version="1.0" encoding="utf-8"?>
+<root>
+  <!--
+    Microsoft ResX Schema 
+
+    Version 2.0
+
+    The primary goals of this format is to allow a simple XML format
+    that is mostly human readable. The generation and parsing of the
+    various data types are done through the TypeConverter classes
+    associated with the data types.
+
+    Example:
+
+    ... ado.net/XML headers & schema ...
+    <resheader name="resmimetype">text/microsoft-resx</resheader>
+    <resheader name="version">2.0</resheader>
+    <resheader name="reader">System.Resources.ResXResourceReader, System.Windows.Forms, ...</resheader>
+    <resheader name="writer">System.Resources.ResXResourceWriter, System.Windows.Forms, ...</resheader>
+    <data name="Name1"><value>this is my long string</value><comment>this is a comment</comment></data>
+    <data name="Color1" type="System.Drawing.Color, System.Drawing">Blue</data>
+    <data name="Bitmap1" mimetype="application/x-microsoft.net.object.binary.base64">
+        <value>[base64 mime encoded serialized .NET Framework object]</value>
+    </data>
+    <data name="Icon1" type="System.Drawing.Icon, System.Drawing" mimetype="application/x-microsoft.net.object.bytearray.base64">
+        <value>[base64 mime encoded string representing a byte array form of the .NET Framework object]</value>
+        <comment>This is a comment</comment>
+    </data>
+
+    There are any number of "resheader" rows that contain simple
+    name/value pairs.
+
+    Each data row contains a name, and value. The row also contains a
+    type or mimetype. Type corresponds to a .NET class that support
+    text/value conversion through the TypeConverter architecture.
+    Classes that don't support this are serialized and stored with the
+    mimetype set.
+
+    The mimetype is used for serialized objects, and tells the
+    ResXResourceReader how to depersist the object. This is currently not
+    extensible. For a given mimetype the value must be set accordingly:
+
+    Note - application/x-microsoft.net.object.binary.base64 is the format
+    that the ResXResourceWriter will generate, however the reader can
+    read any of the formats listed below.
+
+    mimetype: application/x-microsoft.net.object.binary.base64
+    value   : The object must be serialized with
+            : System.Runtime.Serialization.Formatters.Binary.BinaryFormatter
+            : and then encoded with base64 encoding.
+    
+    mimetype: application/x-microsoft.net.object.soap.base64
+    value   : The object must be serialized with
+            : System.Runtime.Serialization.Formatters.Soap.SoapFormatter
+            : and then encoded with base64 encoding.
+
+    mimetype: application/x-microsoft.net.object.bytearray.base64
+    value   : The object must be serialized into a byte array
+            : using a System.ComponentModel.TypeConverter
+            : and then encoded with base64 encoding.
+    -->
+  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
+    <xsd:import namespace="http://www.w3.org/XML/1998/namespace" />
+    <xsd:element name="root" msdata:IsDataSet="true">
+      <xsd:complexType>
+        <xsd:choice maxOccurs="unbounded">
+          <xsd:element name="metadata">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" />
+              </xsd:sequence>
+              <xsd:attribute name="name" use="required" type="xsd:string" />
+              <xsd:attribute name="type" type="xsd:string" />
+              <xsd:attribute name="mimetype" type="xsd:string" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="assembly">
+            <xsd:complexType>
+              <xsd:attribute name="alias" type="xsd:string" />
+              <xsd:attribute name="name" type="xsd:string" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="data">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" msdata:Ordinal="1" />
+              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />
+              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="resheader">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" />
+            </xsd:complexType>
+          </xsd:element>
+        </xsd:choice>
+      </xsd:complexType>
+    </xsd:element>
+  </xsd:schema>
+  <resheader name="resmimetype">
+    <value>text/microsoft-resx</value>
+  </resheader>
+  <resheader name="version">
+    <value>2.0</value>
+  </resheader>
+  <resheader name="reader">
+    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+  <resheader name="writer">
+    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+</root>

BulletinBoard/BulletinBoard/RegionsForm/ListRegionsForm.Designer.cs

@@ -0,0 +1,74 @@
+namespace WebsiteForPlacingAds
+{
+    partial class ListRegionsForm
+    {
+        /// <summary>
+        /// Required designer variable.
+        /// </summary>
+        private System.ComponentModel.IContainer components = null;
+
+        /// <summary>
+        /// Clean up any resources being used.
+        /// </summary>
+        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
+        protected override void Dispose(bool disposing)
+        {
+            if (disposing && (components != null))
+            {
+                components.Dispose();
+            }
+            base.Dispose(disposing);
+        }
+
+        #region Windows Form Designer generated code
+
+        /// <summary>
+        /// Required method for Designer support - do not modify
+        /// the contents of this method with the code editor.
+        /// </summary>
+        private void InitializeComponent()
+        {
+            label1 = new Label();
+            labelListRegions = new Label();
+            SuspendLayout();
+            // 
+            // label1
+            // 
+            label1.AutoSize = true;
+            label1.BackColor = SystemColors.Control;
+            label1.Font = new Font("Segoe UI", 11F, FontStyle.Regular, GraphicsUnit.Point);
+            label1.Location = new Point(10, 7);
+            label1.Name = "label1";
+            label1.Size = new Size(130, 20);
+            label1.TabIndex = 0;
+            label1.Text = "Список регионов";
+            // 
+            // labelListRegions
+            // 
+            labelListRegions.AutoSize = true;
+            labelListRegions.Font = new Font("Segoe UI", 10F, FontStyle.Regular, GraphicsUnit.Point);
+            labelListRegions.Location = new Point(10, 35);
+            labelListRegions.Name = "labelListRegions";
+            labelListRegions.Size = new Size(0, 19);
+            labelListRegions.TabIndex = 1;
+            // 
+            // ListRegionsForm
+            // 
+            AutoScaleDimensions = new SizeF(7F, 15F);
+            AutoScaleMode = AutoScaleMode.Font;
+            ClientSize = new Size(700, 338);
+            Controls.Add(labelListRegions);
+            Controls.Add(label1);
+            Margin = new Padding(3, 2, 3, 2);
+            Name = "ListRegionsForm";
+            Text = "Список регионов";
+            ResumeLayout(false);
+            PerformLayout();
+        }
+
+        #endregion
+
+        private Label label1;
+        private Label labelListRegions;
+    }
+}

BulletinBoard/BulletinBoard/RegionsForm/ListRegionsForm.cs

@@ -0,0 +1,42 @@
+using System;
+using System.Collections.Generic;
+using System.ComponentModel;
+using System.Data;
+using System.Drawing;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using System.Windows.Forms;
+using System.Windows.Forms.VisualStyles;
+
+namespace WebsiteForPlacingAds
+{
+    public partial class ListRegionsForm : Form
+    {
+        AbstractManagmentDatabase managmentDatabase;
+        public ListRegionsForm(AbstractManagmentDatabase managmentDatabase)
+        {
+            InitializeComponent();
+            this.managmentDatabase = managmentDatabase;
+            LoadData();
+        }
+
+        private void LoadData()
+        {
+            DateTime start = DateTime.Now;
+
+            DataTable result = managmentDatabase.getAllEntry("Regions");
+            string listRegions = "";
+            for (int i = 0; i < result.Rows.Count; i++)
+            {
+                listRegions += managmentDatabase.getRowTableById(result, "regions_id", i).ToString() + " | " +
+                                managmentDatabase.getRowTableById(result, "name", i).ToString() + "\n";
+            }
+            labelListRegions.Text = listRegions;
+
+            DateTime end = DateTime.Now;
+            TimeSpan duration = end - start;
+            MessageBox.Show($"Добавлено! Время выполнения: {duration.TotalMilliseconds} мс");
+        }
+    }
+}

BulletinBoard/BulletinBoard/RegionsForm/ListRegionsForm.resx

@@ -0,0 +1,120 @@
+<?xml version="1.0" encoding="utf-8"?>
+<root>
+  <!--
+    Microsoft ResX Schema 
+
+    Version 2.0
+
+    The primary goals of this format is to allow a simple XML format
+    that is mostly human readable. The generation and parsing of the
+    various data types are done through the TypeConverter classes
+    associated with the data types.
+
+    Example:
+
+    ... ado.net/XML headers & schema ...
+    <resheader name="resmimetype">text/microsoft-resx</resheader>
+    <resheader name="version">2.0</resheader>
+    <resheader name="reader">System.Resources.ResXResourceReader, System.Windows.Forms, ...</resheader>
+    <resheader name="writer">System.Resources.ResXResourceWriter, System.Windows.Forms, ...</resheader>
+    <data name="Name1"><value>this is my long string</value><comment>this is a comment</comment></data>
+    <data name="Color1" type="System.Drawing.Color, System.Drawing">Blue</data>
+    <data name="Bitmap1" mimetype="application/x-microsoft.net.object.binary.base64">
+        <value>[base64 mime encoded serialized .NET Framework object]</value>
+    </data>
+    <data name="Icon1" type="System.Drawing.Icon, System.Drawing" mimetype="application/x-microsoft.net.object.bytearray.base64">
+        <value>[base64 mime encoded string representing a byte array form of the .NET Framework object]</value>
+        <comment>This is a comment</comment>
+    </data>
+
+    There are any number of "resheader" rows that contain simple
+    name/value pairs.
+
+    Each data row contains a name, and value. The row also contains a
+    type or mimetype. Type corresponds to a .NET class that support
+    text/value conversion through the TypeConverter architecture.
+    Classes that don't support this are serialized and stored with the
+    mimetype set.
+
+    The mimetype is used for serialized objects, and tells the
+    ResXResourceReader how to depersist the object. This is currently not
+    extensible. For a given mimetype the value must be set accordingly:
+
+    Note - application/x-microsoft.net.object.binary.base64 is the format
+    that the ResXResourceWriter will generate, however the reader can
+    read any of the formats listed below.
+
+    mimetype: application/x-microsoft.net.object.binary.base64
+    value   : The object must be serialized with
+            : System.Runtime.Serialization.Formatters.Binary.BinaryFormatter
+            : and then encoded with base64 encoding.
+    
+    mimetype: application/x-microsoft.net.object.soap.base64
+    value   : The object must be serialized with
+            : System.Runtime.Serialization.Formatters.Soap.SoapFormatter
+            : and then encoded with base64 encoding.
+
+    mimetype: application/x-microsoft.net.object.bytearray.base64
+    value   : The object must be serialized into a byte array
+            : using a System.ComponentModel.TypeConverter
+            : and then encoded with base64 encoding.
+    -->
+  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
+    <xsd:import namespace="http://www.w3.org/XML/1998/namespace" />
+    <xsd:element name="root" msdata:IsDataSet="true">
+      <xsd:complexType>
+        <xsd:choice maxOccurs="unbounded">
+          <xsd:element name="metadata">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" />
+              </xsd:sequence>
+              <xsd:attribute name="name" use="required" type="xsd:string" />
+              <xsd:attribute name="type" type="xsd:string" />
+              <xsd:attribute name="mimetype" type="xsd:string" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="assembly">
+            <xsd:complexType>
+              <xsd:attribute name="alias" type="xsd:string" />
+              <xsd:attribute name="name" type="xsd:string" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="data">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" msdata:Ordinal="1" />
+              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />
+              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="resheader">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" />
+            </xsd:complexType>
+          </xsd:element>
+        </xsd:choice>
+      </xsd:complexType>
+    </xsd:element>
+  </xsd:schema>
+  <resheader name="resmimetype">
+    <value>text/microsoft-resx</value>
+  </resheader>
+  <resheader name="version">
+    <value>2.0</value>
+  </resheader>
+  <resheader name="reader">
+    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+  <resheader name="writer">
+    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+</root>

BulletinBoard/BulletinBoard/RegionsForm/UpdateRegionsForm.Designer.cs

@@ -0,0 +1,109 @@
+namespace WebsiteForPlacingAds
+{
+    partial class UpdateRegionsForm
+    {
+        /// <summary>
+        /// Required designer variable.
+        /// </summary>
+        private System.ComponentModel.IContainer components = null;
+
+        /// <summary>
+        /// Clean up any resources being used.
+        /// </summary>
+        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
+        protected override void Dispose(bool disposing)
+        {
+            if (disposing && (components != null))
+            {
+                components.Dispose();
+            }
+            base.Dispose(disposing);
+        }
+
+        #region Windows Form Designer generated code
+
+        /// <summary>
+        /// Required method for Designer support - do not modify
+        /// the contents of this method with the code editor.
+        /// </summary>
+        private void InitializeComponent()
+        {
+            label1 = new Label();
+            comboBoxUpdateRegion = new ComboBox();
+            textBoxName = new TextBox();
+            labelName = new Label();
+            buttonUpdateRegion = new Button();
+            SuspendLayout();
+            // 
+            // label1
+            // 
+            label1.AutoSize = true;
+            label1.Location = new Point(51, 15);
+            label1.Name = "label1";
+            label1.Size = new Size(251, 15);
+            label1.TabIndex = 33;
+            label1.Text = "Выберите регион, которую хотите обновить";
+            // 
+            // comboBoxUpdateRegion
+            // 
+            comboBoxUpdateRegion.FormattingEnabled = true;
+            comboBoxUpdateRegion.Location = new Point(10, 39);
+            comboBoxUpdateRegion.Margin = new Padding(3, 2, 3, 2);
+            comboBoxUpdateRegion.Name = "comboBoxUpdateRegion";
+            comboBoxUpdateRegion.Size = new Size(377, 23);
+            comboBoxUpdateRegion.TabIndex = 34;
+            comboBoxUpdateRegion.SelectedIndexChanged += comboBoxUpdateRegion_SelectedIndexChanged;
+            // 
+            // textBoxName
+            // 
+            textBoxName.Location = new Point(78, 96);
+            textBoxName.Margin = new Padding(3, 2, 3, 2);
+            textBoxName.Name = "textBoxName";
+            textBoxName.Size = new Size(239, 23);
+            textBoxName.TabIndex = 37;
+            // 
+            // labelName
+            // 
+            labelName.AutoSize = true;
+            labelName.Location = new Point(78, 78);
+            labelName.Name = "labelName";
+            labelName.Size = new Size(59, 15);
+            labelName.TabIndex = 36;
+            labelName.Text = "Название";
+            // 
+            // buttonUpdateRegion
+            // 
+            buttonUpdateRegion.Location = new Point(78, 140);
+            buttonUpdateRegion.Margin = new Padding(3, 2, 3, 2);
+            buttonUpdateRegion.Name = "buttonUpdateRegion";
+            buttonUpdateRegion.Size = new Size(239, 29);
+            buttonUpdateRegion.TabIndex = 35;
+            buttonUpdateRegion.Text = "Обновить регион";
+            buttonUpdateRegion.UseVisualStyleBackColor = true;
+            buttonUpdateRegion.Click += buttonUpdateRegion_Click_1;
+            // 
+            // UpdateRegionsForm
+            // 
+            AutoScaleDimensions = new SizeF(7F, 15F);
+            AutoScaleMode = AutoScaleMode.Font;
+            ClientSize = new Size(397, 190);
+            Controls.Add(textBoxName);
+            Controls.Add(labelName);
+            Controls.Add(buttonUpdateRegion);
+            Controls.Add(comboBoxUpdateRegion);
+            Controls.Add(label1);
+            Margin = new Padding(3, 2, 3, 2);
+            Name = "UpdateRegionsForm";
+            Text = "Обновить регион";
+            ResumeLayout(false);
+            PerformLayout();
+        }
+
+        #endregion
+        private Label label1;
+        private ComboBox comboBoxUpdateRegion;
+        private TextBox textBoxName;
+        private Label labelName;
+        private Button buttonUpdateRegion;
+    }
+}

BulletinBoard/BulletinBoard/RegionsForm/UpdateRegionsForm.cs

@@ -0,0 +1,86 @@
+using System;
+using System.Collections.Generic;
+using System.ComponentModel;
+using System.Data;
+using System.Drawing;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using System.Windows.Forms;
+
+namespace WebsiteForPlacingAds
+{
+    public partial class UpdateRegionsForm : Form
+    {
+        AbstractManagmentDatabase managmentDatabase;
+        public UpdateRegionsForm(AbstractManagmentDatabase managmentDatabase)
+        {
+            InitializeComponent();
+            this.managmentDatabase = managmentDatabase;
+            LoadData();
+        }
+        public void LoadData()
+        {
+            comboBoxUpdateRegion.Items.Clear();
+            DataTable result = managmentDatabase.getAllEntry("Regions");
+            string Regions = "";
+            for (int i = 0; i < result.Rows.Count; i++)
+            {
+                Regions = result.Rows[i]["regions_id"].ToString() + " | " +
+                                (string)result.Rows[i]["name"] + "\n";
+                comboBoxUpdateRegion.Items.Add(Regions);
+            }
+        }
+        public void LoadDataSelectedItem(int regions_id)
+        {
+            DataTable result = managmentDatabase.getEntryById("regions", regions_id);
+            textBoxName.Text = managmentDatabase.getRowTableById(result, "name", 0).ToString();
+        }
+
+        private void comboBoxUpdateRegion_SelectedIndexChanged(object sender, EventArgs e)
+        {
+            string[] selectedItems = comboBoxUpdateRegion.SelectedItem.ToString().Split("|");
+            int region_id = int.Parse(selectedItems[0].Trim());
+            LoadDataSelectedItem(region_id);
+        }
+
+        private void buttonUpdateRegion_Click_1(object sender, EventArgs e)
+        {
+            string[] selectedCategory = comboBoxUpdateRegion.SelectedItem.ToString().Split("|");
+            int region_id = int.Parse(selectedCategory[0].Trim());
+
+            string query = $"UPDATE Regions SET ";
+            int len = query.Length;
+
+
+            string oldName = managmentDatabase.getRowTableById("regions", "name", region_id).ToString();
+
+            string newName = textBoxName.Text;
+
+
+            query = oldName == newName ? query : query + $"name = '{newName}', ";
+            if (len != query.Length)
+            {
+                query = query.TrimEnd(' ');
+                query = query.TrimEnd(',');
+                query += $" WHERE Regions_ID = {region_id};";
+            }
+            try
+            {
+                DateTime start = DateTime.Now;
+
+                managmentDatabase.ExecuteNonQuery(query);
+                MessageBox.Show("Данные успешно обновлены!");
+
+                DateTime end = DateTime.Now;
+                TimeSpan duration = end - start;
+                MessageBox.Show($"Добавлено! Время выполнения: {duration.TotalMilliseconds} мс");
+            }
+            catch (Exception)
+            {
+
+                MessageBox.Show("Данные не обновились");
+            }
+        }
+    }
+}

BulletinBoard/BulletinBoard/RegionsForm/UpdateRegionsForm.resx

@@ -0,0 +1,120 @@
+<?xml version="1.0" encoding="utf-8"?>
+<root>
+  <!--
+    Microsoft ResX Schema 
+
+    Version 2.0
+
+    The primary goals of this format is to allow a simple XML format
+    that is mostly human readable. The generation and parsing of the
+    various data types are done through the TypeConverter classes
+    associated with the data types.
+
+    Example:
+
+    ... ado.net/XML headers & schema ...
+    <resheader name="resmimetype">text/microsoft-resx</resheader>
+    <resheader name="version">2.0</resheader>
+    <resheader name="reader">System.Resources.ResXResourceReader, System.Windows.Forms, ...</resheader>
+    <resheader name="writer">System.Resources.ResXResourceWriter, System.Windows.Forms, ...</resheader>
+    <data name="Name1"><value>this is my long string</value><comment>this is a comment</comment></data>
+    <data name="Color1" type="System.Drawing.Color, System.Drawing">Blue</data>
+    <data name="Bitmap1" mimetype="application/x-microsoft.net.object.binary.base64">
+        <value>[base64 mime encoded serialized .NET Framework object]</value>
+    </data>
+    <data name="Icon1" type="System.Drawing.Icon, System.Drawing" mimetype="application/x-microsoft.net.object.bytearray.base64">
+        <value>[base64 mime encoded string representing a byte array form of the .NET Framework object]</value>
+        <comment>This is a comment</comment>
+    </data>
+
+    There are any number of "resheader" rows that contain simple
+    name/value pairs.
+
+    Each data row contains a name, and value. The row also contains a
+    type or mimetype. Type corresponds to a .NET class that support
+    text/value conversion through the TypeConverter architecture.
+    Classes that don't support this are serialized and stored with the
+    mimetype set.
+
+    The mimetype is used for serialized objects, and tells the
+    ResXResourceReader how to depersist the object. This is currently not
+    extensible. For a given mimetype the value must be set accordingly:
+
+    Note - application/x-microsoft.net.object.binary.base64 is the format
+    that the ResXResourceWriter will generate, however the reader can
+    read any of the formats listed below.
+
+    mimetype: application/x-microsoft.net.object.binary.base64
+    value   : The object must be serialized with
+            : System.Runtime.Serialization.Formatters.Binary.BinaryFormatter
+            : and then encoded with base64 encoding.
+    
+    mimetype: application/x-microsoft.net.object.soap.base64
+    value   : The object must be serialized with
+            : System.Runtime.Serialization.Formatters.Soap.SoapFormatter
+            : and then encoded with base64 encoding.
+
+    mimetype: application/x-microsoft.net.object.bytearray.base64
+    value   : The object must be serialized into a byte array
+            : using a System.ComponentModel.TypeConverter
+            : and then encoded with base64 encoding.
+    -->
+  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
+    <xsd:import namespace="http://www.w3.org/XML/1998/namespace" />
+    <xsd:element name="root" msdata:IsDataSet="true">
+      <xsd:complexType>
+        <xsd:choice maxOccurs="unbounded">
+          <xsd:element name="metadata">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" />
+              </xsd:sequence>
+              <xsd:attribute name="name" use="required" type="xsd:string" />
+              <xsd:attribute name="type" type="xsd:string" />
+              <xsd:attribute name="mimetype" type="xsd:string" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="assembly">
+            <xsd:complexType>
+              <xsd:attribute name="alias" type="xsd:string" />
+              <xsd:attribute name="name" type="xsd:string" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="data">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" msdata:Ordinal="1" />
+              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />
+              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="resheader">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" />
+            </xsd:complexType>
+          </xsd:element>
+        </xsd:choice>
+      </xsd:complexType>
+    </xsd:element>
+  </xsd:schema>
+  <resheader name="resmimetype">
+    <value>text/microsoft-resx</value>
+  </resheader>
+  <resheader name="version">
+    <value>2.0</value>
+  </resheader>
+  <resheader name="reader">
+    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+  <resheader name="writer">
+    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+</root>

BulletinBoard/BulletinBoard/SubcategoriesForm/CreateSubcategoriesForm.Designer.cs

@@ -0,0 +1,109 @@
+namespace WebsiteForPlacingAds
+{
+    partial class CreateSubcategoriesForm
+    {
+        /// <summary>
+        ///  Required designer variable.
+        /// </summary>
+        private System.ComponentModel.IContainer components = null;
+
+        /// <summary>
+        ///  Clean up any resources being used.
+        /// </summary>
+        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
+        protected override void Dispose(bool disposing)
+        {
+            if (disposing && (components != null))
+            {
+                components.Dispose();
+            }
+            base.Dispose(disposing);
+        }
+
+        #region Windows Form Designer generated code
+
+        /// <summary>
+        ///  Required method for Designer support - do not modify
+        ///  the contents of this method with the code editor.
+        /// </summary>
+        private void InitializeComponent()
+        {
+            textBoxName = new TextBox();
+            labelName = new Label();
+            buttonCreateSubcategory = new Button();
+            comboBoxCategory = new ComboBox();
+            labelCategory = new Label();
+            SuspendLayout();
+            // 
+            // textBoxName
+            // 
+            textBoxName.Location = new Point(37, 35);
+            textBoxName.Margin = new Padding(3, 2, 3, 2);
+            textBoxName.Name = "textBoxName";
+            textBoxName.Size = new Size(239, 23);
+            textBoxName.TabIndex = 5;
+            // 
+            // labelName
+            // 
+            labelName.AutoSize = true;
+            labelName.Location = new Point(37, 17);
+            labelName.Name = "labelName";
+            labelName.Size = new Size(59, 15);
+            labelName.TabIndex = 4;
+            labelName.Text = "Название";
+            // 
+            // buttonCreateSubcategory
+            // 
+            buttonCreateSubcategory.Location = new Point(37, 118);
+            buttonCreateSubcategory.Margin = new Padding(3, 2, 3, 2);
+            buttonCreateSubcategory.Name = "buttonCreateSubcategory";
+            buttonCreateSubcategory.Size = new Size(239, 29);
+            buttonCreateSubcategory.TabIndex = 3;
+            buttonCreateSubcategory.Text = "Добавить подкатегорию";
+            buttonCreateSubcategory.UseVisualStyleBackColor = true;
+            buttonCreateSubcategory.Click += buttonCreateSubcategory_Click_1;
+            // 
+            // comboBoxCategory
+            // 
+            comboBoxCategory.FormattingEnabled = true;
+            comboBoxCategory.Location = new Point(37, 83);
+            comboBoxCategory.Margin = new Padding(3, 2, 3, 2);
+            comboBoxCategory.Name = "comboBoxCategory";
+            comboBoxCategory.Size = new Size(239, 23);
+            comboBoxCategory.TabIndex = 17;
+            // 
+            // labelCategory
+            // 
+            labelCategory.AutoSize = true;
+            labelCategory.Location = new Point(37, 67);
+            labelCategory.Name = "labelCategory";
+            labelCategory.Size = new Size(63, 15);
+            labelCategory.TabIndex = 18;
+            labelCategory.Text = "Категория";
+            // 
+            // CreateSubcategoriesForm
+            // 
+            AutoScaleDimensions = new SizeF(7F, 15F);
+            AutoScaleMode = AutoScaleMode.Font;
+            ClientSize = new Size(324, 158);
+            Controls.Add(labelCategory);
+            Controls.Add(comboBoxCategory);
+            Controls.Add(textBoxName);
+            Controls.Add(labelName);
+            Controls.Add(buttonCreateSubcategory);
+            Margin = new Padding(3, 2, 3, 2);
+            Name = "CreateSubcategoriesForm";
+            Text = "Подкатегория";
+            ResumeLayout(false);
+            PerformLayout();
+        }
+
+        #endregion
+
+        private TextBox textBoxName;
+        private Label labelName;
+        private Button buttonCreateSubcategory;
+        private ComboBox comboBoxCategory;
+        private Label labelCategory;
+    }
+}

BulletinBoard/BulletinBoard/SubcategoriesForm/CreateSubcategoriesForm.cs

@@ -0,0 +1,56 @@
+using System.Data;
+
+namespace WebsiteForPlacingAds
+{
+    public partial class CreateSubcategoriesForm : Form
+    {
+        AbstractManagmentDatabase managmentDatabase;
+        public CreateSubcategoriesForm(AbstractManagmentDatabase managmentDatabase)
+        {
+            InitializeComponent();
+            this.managmentDatabase = managmentDatabase;
+            LoadData();
+        }
+
+        private void buttonCreateSubcategory_Click_1(object sender, EventArgs e)
+        {
+            string name = textBoxName.Text;
+            string[] category = comboBoxCategory.SelectedItem.ToString().Split(" ");
+
+            string category_id = category[0];
+
+
+            try
+            {
+                DateTime start = DateTime.Now;
+
+                managmentDatabase.insertInto("subcategories", $"'{name}'", category_id);
+                MessageBox.Show("Äîáàâëåíî!");
+                LoadData();
+
+                DateTime end = DateTime.Now;
+                TimeSpan duration = end - start;
+                MessageBox.Show($"Äîáàâëåíî! Âðåìÿ âûïîëíåíèÿ: {duration.TotalMilliseconds} ìñ");
+
+                // Çàêðûòü òåêóùóþ ôîðìó ïîñëå âûïîëíåíèÿ äåéñòâèé
+                this.Close();
+            }
+            catch (Exception ex)
+            {
+                MessageBox.Show("Íå óäàëîñü äîáàâèòü");
+            }
+        }
+
+        private void LoadData()
+        {
+            comboBoxCategory.Items.Clear();
+            DataTable result = managmentDatabase.getAllEntry("CATEGORIES");
+            string[] id_names = new string[result.Rows.Count];
+            for (int i = 0; i < result.Rows.Count; i++)
+            {
+                id_names[i] = managmentDatabase.getRowTableById(result, "categories_id", i).ToString() + ". " + managmentDatabase.getRowTableById(result, "name", i).ToString();
+                comboBoxCategory.Items.Add(id_names[i]);
+            }
+        }
+    }
+}

BulletinBoard/BulletinBoard/SubcategoriesForm/CreateSubcategoriesForm.resx

@@ -0,0 +1,120 @@
+<?xml version="1.0" encoding="utf-8"?>
+<root>
+  <!--
+    Microsoft ResX Schema 
+
+    Version 2.0
+
+    The primary goals of this format is to allow a simple XML format
+    that is mostly human readable. The generation and parsing of the
+    various data types are done through the TypeConverter classes
+    associated with the data types.
+
+    Example:
+
+    ... ado.net/XML headers & schema ...
+    <resheader name="resmimetype">text/microsoft-resx</resheader>
+    <resheader name="version">2.0</resheader>
+    <resheader name="reader">System.Resources.ResXResourceReader, System.Windows.Forms, ...</resheader>
+    <resheader name="writer">System.Resources.ResXResourceWriter, System.Windows.Forms, ...</resheader>
+    <data name="Name1"><value>this is my long string</value><comment>this is a comment</comment></data>
+    <data name="Color1" type="System.Drawing.Color, System.Drawing">Blue</data>
+    <data name="Bitmap1" mimetype="application/x-microsoft.net.object.binary.base64">
+        <value>[base64 mime encoded serialized .NET Framework object]</value>
+    </data>
+    <data name="Icon1" type="System.Drawing.Icon, System.Drawing" mimetype="application/x-microsoft.net.object.bytearray.base64">
+        <value>[base64 mime encoded string representing a byte array form of the .NET Framework object]</value>
+        <comment>This is a comment</comment>
+    </data>
+
+    There are any number of "resheader" rows that contain simple
+    name/value pairs.
+
+    Each data row contains a name, and value. The row also contains a
+    type or mimetype. Type corresponds to a .NET class that support
+    text/value conversion through the TypeConverter architecture.
+    Classes that don't support this are serialized and stored with the
+    mimetype set.
+
+    The mimetype is used for serialized objects, and tells the
+    ResXResourceReader how to depersist the object. This is currently not
+    extensible. For a given mimetype the value must be set accordingly:
+
+    Note - application/x-microsoft.net.object.binary.base64 is the format
+    that the ResXResourceWriter will generate, however the reader can
+    read any of the formats listed below.
+
+    mimetype: application/x-microsoft.net.object.binary.base64
+    value   : The object must be serialized with
+            : System.Runtime.Serialization.Formatters.Binary.BinaryFormatter
+            : and then encoded with base64 encoding.
+    
+    mimetype: application/x-microsoft.net.object.soap.base64
+    value   : The object must be serialized with
+            : System.Runtime.Serialization.Formatters.Soap.SoapFormatter
+            : and then encoded with base64 encoding.
+
+    mimetype: application/x-microsoft.net.object.bytearray.base64
+    value   : The object must be serialized into a byte array
+            : using a System.ComponentModel.TypeConverter
+            : and then encoded with base64 encoding.
+    -->
+  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
+    <xsd:import namespace="http://www.w3.org/XML/1998/namespace" />
+    <xsd:element name="root" msdata:IsDataSet="true">
+      <xsd:complexType>
+        <xsd:choice maxOccurs="unbounded">
+          <xsd:element name="metadata">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" />
+              </xsd:sequence>
+              <xsd:attribute name="name" use="required" type="xsd:string" />
+              <xsd:attribute name="type" type="xsd:string" />
+              <xsd:attribute name="mimetype" type="xsd:string" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="assembly">
+            <xsd:complexType>
+              <xsd:attribute name="alias" type="xsd:string" />
+              <xsd:attribute name="name" type="xsd:string" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="data">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" msdata:Ordinal="1" />
+              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />
+              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="resheader">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" />
+            </xsd:complexType>
+          </xsd:element>
+        </xsd:choice>
+      </xsd:complexType>
+    </xsd:element>
+  </xsd:schema>
+  <resheader name="resmimetype">
+    <value>text/microsoft-resx</value>
+  </resheader>
+  <resheader name="version">
+    <value>2.0</value>
+  </resheader>
+  <resheader name="reader">
+    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+  <resheader name="writer">
+    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+</root>

BulletinBoard/BulletinBoard/SubcategoriesForm/DeleteSubcategoriesForm.Designer.cs

@@ -0,0 +1,87 @@
+namespace WebsiteForPlacingAds
+{
+    partial class DeleteSubcategoriesForm
+    {
+        /// <summary>
+        /// Required designer variable.
+        /// </summary>
+        private System.ComponentModel.IContainer components = null;
+
+        /// <summary>
+        /// Clean up any resources being used.
+        /// </summary>
+        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
+        protected override void Dispose(bool disposing)
+        {
+            if (disposing && (components != null))
+            {
+                components.Dispose();
+            }
+            base.Dispose(disposing);
+        }
+
+        #region Windows Form Designer generated code
+
+        /// <summary>
+        /// Required method for Designer support - do not modify
+        /// the contents of this method with the code editor.
+        /// </summary>
+        private void InitializeComponent()
+        {
+            this.comboBoxDeleteSubcategories = new System.Windows.Forms.ComboBox();
+            this.buttonDeleteSubcategory = new System.Windows.Forms.Button();
+            this.label1 = new System.Windows.Forms.Label();
+            this.SuspendLayout();
+            // 
+            // comboBoxDeleteSubcategories
+            // 
+            this.comboBoxDeleteSubcategories.FormattingEnabled = true;
+            this.comboBoxDeleteSubcategories.Location = new System.Drawing.Point(38, 49);
+            this.comboBoxDeleteSubcategories.Margin = new System.Windows.Forms.Padding(3, 2, 3, 2);
+            this.comboBoxDeleteSubcategories.Name = "comboBoxDeleteSubcategories";
+            this.comboBoxDeleteSubcategories.Size = new System.Drawing.Size(367, 23);
+            this.comboBoxDeleteSubcategories.TabIndex = 5;
+            // 
+            // buttonDeleteSubcategory
+            // 
+            this.buttonDeleteSubcategory.Location = new System.Drawing.Point(135, 86);
+            this.buttonDeleteSubcategory.Margin = new System.Windows.Forms.Padding(3, 2, 3, 2);
+            this.buttonDeleteSubcategory.Name = "buttonDeleteSubcategory";
+            this.buttonDeleteSubcategory.Size = new System.Drawing.Size(163, 28);
+            this.buttonDeleteSubcategory.TabIndex = 4;
+            this.buttonDeleteSubcategory.Text = "Удалить";
+            this.buttonDeleteSubcategory.UseVisualStyleBackColor = true;
+            this.buttonDeleteSubcategory.Click += new System.EventHandler(this.buttonDeleteSubcategory_Click_1);
+            // 
+            // label1
+            // 
+            this.label1.AutoSize = true;
+            this.label1.Location = new System.Drawing.Point(73, 17);
+            this.label1.Name = "label1";
+            this.label1.Size = new System.Drawing.Size(282, 15);
+            this.label1.TabIndex = 3;
+            this.label1.Text = "Выберите подкатегорию, которую хотите удалить";
+            // 
+            // DeleteSubcategoriesForm
+            // 
+            this.AutoScaleDimensions = new System.Drawing.SizeF(7F, 15F);
+            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
+            this.ClientSize = new System.Drawing.Size(442, 131);
+            this.Controls.Add(this.comboBoxDeleteSubcategories);
+            this.Controls.Add(this.buttonDeleteSubcategory);
+            this.Controls.Add(this.label1);
+            this.Margin = new System.Windows.Forms.Padding(3, 2, 3, 2);
+            this.Name = "DeleteSubcategoriesForm";
+            this.Text = "Удалить подкатегорию";
+            this.ResumeLayout(false);
+            this.PerformLayout();
+
+        }
+
+        #endregion
+
+        private ComboBox comboBoxDeleteSubcategories;
+        private Button buttonDeleteSubcategory;
+        private Label label1;
+    }
+}

BulletinBoard/BulletinBoard/SubcategoriesForm/DeleteSubcategoriesForm.cs

@@ -0,0 +1,61 @@
+using System;
+using System.Collections.Generic;
+using System.ComponentModel;
+using System.Data;
+using System.Drawing;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using System.Windows.Forms;
+
+namespace WebsiteForPlacingAds
+{
+    public partial class DeleteSubcategoriesForm : Form
+    {
+        AbstractManagmentDatabase managmentDatabase;
+        private int setval_seq;
+        public DeleteSubcategoriesForm(AbstractManagmentDatabase managmentDatabase)
+        {
+            InitializeComponent();
+            this.managmentDatabase = managmentDatabase;
+            LoadData();
+        }
+        public void LoadData()
+        {
+            comboBoxDeleteSubcategories.Items.Clear();
+            DataTable result = managmentDatabase.getAllEntry("Subcategories");
+            setval_seq = result.Rows.Count;
+            string Subcategories = "";
+            for (int i = 0; i < result.Rows.Count; i++)
+            {
+                setval_seq = Math.Max(Convert.ToInt32(managmentDatabase.getRowTableById(result, "subcategories_id", i)), setval_seq);
+                Subcategories = managmentDatabase.getRowTableById(result, "subcategories_id", i).ToString() + " | " +
+                                managmentDatabase.getRowTableById(result, "name", i).ToString() + "\n";
+                comboBoxDeleteSubcategories.Items.Add(Subcategories);
+            }
+        }
+
+        private void buttonDeleteSubcategory_Click_1(object sender, EventArgs e)
+        {
+            string[] subcategories = comboBoxDeleteSubcategories.SelectedItem.ToString().Split("|");
+            string subcategory_id = subcategories[0].Trim();
+            try
+            {
+                DateTime start = DateTime.Now;
+
+                managmentDatabase.deleteEntry("subcategories", int.Parse(subcategory_id));
+                LoadData();
+                if (setval_seq > 0) managmentDatabase.reduceSeq("seq_subcategories", setval_seq);
+                MessageBox.Show("Удалено!");
+
+                DateTime end = DateTime.Now;
+                TimeSpan duration = end - start;
+                MessageBox.Show($"Добавлено! Время выполнения: {duration.TotalMilliseconds} мс");
+            }
+            catch (Exception ex)
+            {
+                MessageBox.Show("Не удалось удалить");
+            }
+        }
+    }
+}

BulletinBoard/BulletinBoard/SubcategoriesForm/DeleteSubcategoriesForm.resx

@@ -0,0 +1,60 @@
+<root>
+  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
+    <xsd:import namespace="http://www.w3.org/XML/1998/namespace" />
+    <xsd:element name="root" msdata:IsDataSet="true">
+      <xsd:complexType>
+        <xsd:choice maxOccurs="unbounded">
+          <xsd:element name="metadata">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" />
+              </xsd:sequence>
+              <xsd:attribute name="name" use="required" type="xsd:string" />
+              <xsd:attribute name="type" type="xsd:string" />
+              <xsd:attribute name="mimetype" type="xsd:string" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="assembly">
+            <xsd:complexType>
+              <xsd:attribute name="alias" type="xsd:string" />
+              <xsd:attribute name="name" type="xsd:string" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="data">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" msdata:Ordinal="1" />
+              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />
+              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="resheader">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" />
+            </xsd:complexType>
+          </xsd:element>
+        </xsd:choice>
+      </xsd:complexType>
+    </xsd:element>
+  </xsd:schema>
+  <resheader name="resmimetype">
+    <value>text/microsoft-resx</value>
+  </resheader>
+  <resheader name="version">
+    <value>2.0</value>
+  </resheader>
+  <resheader name="reader">
+    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+  <resheader name="writer">
+    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+</root>

BulletinBoard/BulletinBoard/SubcategoriesForm/ListSubcategoriesForm.Designer.cs

@@ -0,0 +1,75 @@
+namespace WebsiteForPlacingAds
+{
+    partial class ListSubcategoriesForm
+    {
+        /// <summary>
+        /// Required designer variable.
+        /// </summary>
+        private System.ComponentModel.IContainer components = null;
+
+        /// <summary>
+        /// Clean up any resources being used.
+        /// </summary>
+        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
+        protected override void Dispose(bool disposing)
+        {
+            if (disposing && (components != null))
+            {
+                components.Dispose();
+            }
+            base.Dispose(disposing);
+        }
+
+        #region Windows Form Designer generated code
+
+        /// <summary>
+        /// Required method for Designer support - do not modify
+        /// the contents of this method with the code editor.
+        /// </summary>
+        private void InitializeComponent()
+        {
+            this.label1 = new System.Windows.Forms.Label();
+            this.labelListSubcategories = new System.Windows.Forms.Label();
+            this.SuspendLayout();
+            // 
+            // label1
+            // 
+            this.label1.AutoSize = true;
+            this.label1.BackColor = System.Drawing.SystemColors.Control;
+            this.label1.Font = new System.Drawing.Font("Segoe UI", 11F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point);
+            this.label1.Location = new System.Drawing.Point(10, 7);
+            this.label1.Name = "label1";
+            this.label1.Size = new System.Drawing.Size(160, 20);
+            this.label1.TabIndex = 0;
+            this.label1.Text = "Список подкатегорий";
+            // 
+            // labelListSubcategories
+            // 
+            this.labelListSubcategories.AutoSize = true;
+            this.labelListSubcategories.Font = new System.Drawing.Font("Segoe UI", 10F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point);
+            this.labelListSubcategories.Location = new System.Drawing.Point(10, 35);
+            this.labelListSubcategories.Name = "labelListSubcategories";
+            this.labelListSubcategories.Size = new System.Drawing.Size(0, 19);
+            this.labelListSubcategories.TabIndex = 1;
+            // 
+            // ListSubcategoriesForm
+            // 
+            this.AutoScaleDimensions = new System.Drawing.SizeF(7F, 15F);
+            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
+            this.ClientSize = new System.Drawing.Size(700, 338);
+            this.Controls.Add(this.labelListSubcategories);
+            this.Controls.Add(this.label1);
+            this.Margin = new System.Windows.Forms.Padding(3, 2, 3, 2);
+            this.Name = "ListSubcategoriesForm";
+            this.Text = "Список подкатегорий";
+            this.ResumeLayout(false);
+            this.PerformLayout();
+
+        }
+
+        #endregion
+
+        private Label label1;
+        private Label labelListSubcategories;
+    }
+}

BulletinBoard/BulletinBoard/SubcategoriesForm/ListSubcategoriesForm.cs

@@ -0,0 +1,42 @@
+using System;
+using System.Collections.Generic;
+using System.ComponentModel;
+using System.Data;
+using System.Drawing;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using System.Windows.Forms;
+using System.Windows.Forms.VisualStyles;
+
+namespace WebsiteForPlacingAds
+{
+    public partial class ListSubcategoriesForm : Form
+    {
+        AbstractManagmentDatabase managmentDatabase;
+        public ListSubcategoriesForm(AbstractManagmentDatabase managmentDatabase)
+        {
+            InitializeComponent();
+            this.managmentDatabase = managmentDatabase;
+            LoadData();
+        }
+
+        private void LoadData()
+        {
+            DateTime start = DateTime.Now;
+
+            DataTable result = managmentDatabase.getAllEntry("Subcategories");
+            string listSubcategories = "";
+            for (int i = 0; i < result.Rows.Count; i++)
+            {
+                listSubcategories += managmentDatabase.getRowTableById(result, "subcategories_id", i).ToString() + " | " +
+                                managmentDatabase.getRowTableById(result, "name", i).ToString() + "\n";
+            }
+            labelListSubcategories.Text = listSubcategories;
+
+            DateTime end = DateTime.Now;
+            TimeSpan duration = end - start;
+            MessageBox.Show($"Добавлено! Время выполнения: {duration.TotalMilliseconds} мс");
+        }
+    }
+}

BulletinBoard/BulletinBoard/SubcategoriesForm/ListSubcategoriesForm.resx

@@ -0,0 +1,60 @@
+<root>
+  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
+    <xsd:import namespace="http://www.w3.org/XML/1998/namespace" />
+    <xsd:element name="root" msdata:IsDataSet="true">
+      <xsd:complexType>
+        <xsd:choice maxOccurs="unbounded">
+          <xsd:element name="metadata">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" />
+              </xsd:sequence>
+              <xsd:attribute name="name" use="required" type="xsd:string" />
+              <xsd:attribute name="type" type="xsd:string" />
+              <xsd:attribute name="mimetype" type="xsd:string" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="assembly">
+            <xsd:complexType>
+              <xsd:attribute name="alias" type="xsd:string" />
+              <xsd:attribute name="name" type="xsd:string" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="data">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" msdata:Ordinal="1" />
+              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />
+              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="resheader">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" />
+            </xsd:complexType>
+          </xsd:element>
+        </xsd:choice>
+      </xsd:complexType>
+    </xsd:element>
+  </xsd:schema>
+  <resheader name="resmimetype">
+    <value>text/microsoft-resx</value>
+  </resheader>
+  <resheader name="version">
+    <value>2.0</value>
+  </resheader>
+  <resheader name="reader">
+    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+  <resheader name="writer">
+    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+</root>

BulletinBoard/BulletinBoard/SubcategoriesForm/UpdateSubcategoriesForm.Designer.cs

@@ -0,0 +1,111 @@
+namespace WebsiteForPlacingAds
+{
+    partial class UpdateSubcategoriesForm
+    {
+        /// <summary>
+        /// Required designer variable.
+        /// </summary>
+        private System.ComponentModel.IContainer components = null;
+
+        /// <summary>
+        /// Clean up any resources being used.
+        /// </summary>
+        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
+        protected override void Dispose(bool disposing)
+        {
+            if (disposing && (components != null))
+            {
+                components.Dispose();
+            }
+            base.Dispose(disposing);
+        }
+
+        #region Windows Form Designer generated code
+
+        /// <summary>
+        /// Required method for Designer support - do not modify
+        /// the contents of this method with the code editor.
+        /// </summary>
+        private void InitializeComponent()
+        {
+            this.textBoxName = new System.Windows.Forms.TextBox();
+            this.labelName = new System.Windows.Forms.Label();
+            this.buttonUpdateSubcategory = new System.Windows.Forms.Button();
+            this.comboBoxUpdateSubcategory = new System.Windows.Forms.ComboBox();
+            this.label1 = new System.Windows.Forms.Label();
+            this.SuspendLayout();
+            // 
+            // textBoxName
+            // 
+            this.textBoxName.Location = new System.Drawing.Point(80, 104);
+            this.textBoxName.Margin = new System.Windows.Forms.Padding(3, 2, 3, 2);
+            this.textBoxName.Name = "textBoxName";
+            this.textBoxName.Size = new System.Drawing.Size(239, 23);
+            this.textBoxName.TabIndex = 42;
+            // 
+            // labelName
+            // 
+            this.labelName.AutoSize = true;
+            this.labelName.Location = new System.Drawing.Point(80, 86);
+            this.labelName.Name = "labelName";
+            this.labelName.Size = new System.Drawing.Size(59, 15);
+            this.labelName.TabIndex = 41;
+            this.labelName.Text = "Название";
+            // 
+            // buttonUpdateSubcategory
+            // 
+            this.buttonUpdateSubcategory.Location = new System.Drawing.Point(80, 148);
+            this.buttonUpdateSubcategory.Margin = new System.Windows.Forms.Padding(3, 2, 3, 2);
+            this.buttonUpdateSubcategory.Name = "buttonUpdateSubcategory";
+            this.buttonUpdateSubcategory.Size = new System.Drawing.Size(239, 29);
+            this.buttonUpdateSubcategory.TabIndex = 40;
+            this.buttonUpdateSubcategory.Text = "Обновить категорию";
+            this.buttonUpdateSubcategory.UseVisualStyleBackColor = true;
+            this.buttonUpdateSubcategory.Click += new System.EventHandler(this.buttonUpdateSubcategory_Click);
+            // 
+            // comboBoxUpdateSubcategory
+            // 
+            this.comboBoxUpdateSubcategory.FormattingEnabled = true;
+            this.comboBoxUpdateSubcategory.Location = new System.Drawing.Point(12, 47);
+            this.comboBoxUpdateSubcategory.Margin = new System.Windows.Forms.Padding(3, 2, 3, 2);
+            this.comboBoxUpdateSubcategory.Name = "comboBoxUpdateSubcategory";
+            this.comboBoxUpdateSubcategory.Size = new System.Drawing.Size(377, 23);
+            this.comboBoxUpdateSubcategory.TabIndex = 39;
+            this.comboBoxUpdateSubcategory.SelectedIndexChanged += new System.EventHandler(this.comboBoxUpdateSubcategory_SelectedIndexChanged_1);
+            // 
+            // label1
+            // 
+            this.label1.AutoSize = true;
+            this.label1.Location = new System.Drawing.Point(53, 23);
+            this.label1.Name = "label1";
+            this.label1.Size = new System.Drawing.Size(291, 15);
+            this.label1.TabIndex = 38;
+            this.label1.Text = "Выберите подкатегорию, которую хотите обновить";
+            // 
+            // UpdateSubcategoriesForm
+            // 
+            this.AutoScaleDimensions = new System.Drawing.SizeF(7F, 15F);
+            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
+            this.ClientSize = new System.Drawing.Size(397, 195);
+            this.Controls.Add(this.textBoxName);
+            this.Controls.Add(this.labelName);
+            this.Controls.Add(this.buttonUpdateSubcategory);
+            this.Controls.Add(this.comboBoxUpdateSubcategory);
+            this.Controls.Add(this.label1);
+            this.Margin = new System.Windows.Forms.Padding(3, 2, 3, 2);
+            this.Name = "UpdateSubcategoriesForm";
+            this.Text = "Обновить подкатегорию";
+            this.ResumeLayout(false);
+            this.PerformLayout();
+
+        }
+
+        #endregion
+
+        private TextBox textBoxName;
+        private Label labelName;
+        private Button buttonUpdateSubcategory;
+        private ComboBox comboBoxUpdateSubcategory;
+        private Label label1;
+    }
+}

BulletinBoard/BulletinBoard/SubcategoriesForm/UpdateSubcategoriesForm.cs

@@ -0,0 +1,88 @@
+using System;
+using System.Collections.Generic;
+using System.ComponentModel;
+using System.Data;
+using System.Drawing;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using System.Windows.Forms;
+
+namespace WebsiteForPlacingAds
+{
+    public partial class UpdateSubcategoriesForm : Form
+    {
+        AbstractManagmentDatabase managmentDatabase;
+        public UpdateSubcategoriesForm(AbstractManagmentDatabase managmentDatabase)
+        {
+            InitializeComponent();
+            this.managmentDatabase = managmentDatabase;
+            LoadData();
+        }
+        public void LoadData()
+        {
+            comboBoxUpdateSubcategory.Items.Clear();
+            DataTable result = managmentDatabase.getAllEntry("Subcategories");
+            string Subcategories = "";
+            for (int i = 0; i < result.Rows.Count; i++)
+            {
+                Subcategories = result.Rows[i]["subcategories_id"].ToString() + " | " +
+                                (string)result.Rows[i]["name"] + "\n";
+                comboBoxUpdateSubcategory.Items.Add(Subcategories);
+            }
+        }
+        public void LoadDataSelectedItem(int subcategories_id)
+        {
+            DataTable result = managmentDatabase.getEntryById("subcategories", subcategories_id);
+            textBoxName.Text = managmentDatabase.getRowTableById(result, "name", 0).ToString();
+        }
+
+
+
+        private void buttonUpdateSubcategory_Click(object sender, EventArgs e)
+        {
+            string[] selectedSubcategory = comboBoxUpdateSubcategory.SelectedItem.ToString().Split("|");
+            int subcategory_id = int.Parse(selectedSubcategory[0].Trim());
+
+            string query = $"UPDATE Subcategories SET ";
+            int len = query.Length;
+
+
+            string oldName = managmentDatabase.getRowTableById("subcategories", "name", subcategory_id).ToString();
+
+            string newName = textBoxName.Text;
+
+
+            query = oldName == newName ? query : query + $"name = '{newName}', ";
+            if (len != query.Length)
+            {
+                query = query.TrimEnd(' ');
+                query = query.TrimEnd(',');
+                query += $" WHERE Subcategories_ID = {subcategory_id};";
+            }
+            try
+            {
+                DateTime start = DateTime.Now;
+
+                managmentDatabase.ExecuteNonQuery(query);
+                MessageBox.Show("Данные успешно обновлены!");
+
+                DateTime end = DateTime.Now;
+                TimeSpan duration = end - start;
+                MessageBox.Show($"Добавлено! Время выполнения: {duration.TotalMilliseconds} мс");
+            }
+            catch (Exception)
+            {
+
+                MessageBox.Show("Данные не обновились");
+            }
+        }
+
+        private void comboBoxUpdateSubcategory_SelectedIndexChanged_1(object sender, EventArgs e)
+        {
+            string[] selectedItems = comboBoxUpdateSubcategory.SelectedItem.ToString().Split("|");
+            int subcategory_id = int.Parse(selectedItems[0].Trim());
+            LoadDataSelectedItem(subcategory_id);
+        }
+    }
+}

BulletinBoard/BulletinBoard/SubcategoriesForm/UpdateSubcategoriesForm.resx

@@ -0,0 +1,60 @@
+<root>
+  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
+    <xsd:import namespace="http://www.w3.org/XML/1998/namespace" />
+    <xsd:element name="root" msdata:IsDataSet="true">
+      <xsd:complexType>
+        <xsd:choice maxOccurs="unbounded">
+          <xsd:element name="metadata">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" />
+              </xsd:sequence>
+              <xsd:attribute name="name" use="required" type="xsd:string" />
+              <xsd:attribute name="type" type="xsd:string" />
+              <xsd:attribute name="mimetype" type="xsd:string" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="assembly">
+            <xsd:complexType>
+              <xsd:attribute name="alias" type="xsd:string" />
+              <xsd:attribute name="name" type="xsd:string" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="data">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" msdata:Ordinal="1" />
+              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />
+              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="resheader">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" />
+            </xsd:complexType>
+          </xsd:element>
+        </xsd:choice>
+      </xsd:complexType>
+    </xsd:element>
+  </xsd:schema>
+  <resheader name="resmimetype">
+    <value>text/microsoft-resx</value>
+  </resheader>
+  <resheader name="version">
+    <value>2.0</value>
+  </resheader>
+  <resheader name="reader">
+    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+  <resheader name="writer">
+    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+</root>