diff --git a/ComputerStoreDatabaseImplement/ComputerStoreDatabase.cs b/ComputerStoreDatabaseImplement/ComputerStoreDatabase.cs
index fd3d783..8d120be 100644
--- a/ComputerStoreDatabaseImplement/ComputerStoreDatabase.cs
+++ b/ComputerStoreDatabaseImplement/ComputerStoreDatabase.cs
@@ -14,7 +14,7 @@ namespace ComputerStoreDatabaseImplement
         {
             if (optionsBuilder.IsConfigured == false)
             {
-                optionsBuilder.UseSqlServer(@"Server=(localdb)\mssqllocaldb;Initial Catalog=ComputerStoreDatabase;Integrated Security=True;MultipleActiveResultSets=True;TrustServerCertificate=True");
+                optionsBuilder.UseSqlServer(@"Data Source=YUEEJKE\SQLEXPRESS;Initial Catalog=ComputerStoreDatabase;Integrated Security=True;MultipleActiveResultSets=True;TrustServerCertificate=True");
             }
             base.OnConfiguring(optionsBuilder);
         }
diff --git a/ComputerStoreDatabaseImplement/Migrations/20230517142400_RelationFixes.Designer.cs b/ComputerStoreDatabaseImplement/Migrations/20230517142400_RelationFixes.Designer.cs
new file mode 100644
index 0000000..f579d22
--- /dev/null
+++ b/ComputerStoreDatabaseImplement/Migrations/20230517142400_RelationFixes.Designer.cs
@@ -0,0 +1,496 @@
+// <auto-generated />
+using System;
+using ComputerStoreDatabaseImplement;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Infrastructure;
+using Microsoft.EntityFrameworkCore.Metadata;
+using Microsoft.EntityFrameworkCore.Migrations;
+using Microsoft.EntityFrameworkCore.Storage.ValueConversion;
+
+#nullable disable
+
+namespace ComputerStoreDatabaseImplement.Migrations
+{
+    [DbContext(typeof(ComputerStoreDatabase))]
+    [Migration("20230517142400_RelationFixes")]
+    partial class RelationFixes
+    {
+        /// <inheritdoc />
+        protected override void BuildTargetModel(ModelBuilder modelBuilder)
+        {
+#pragma warning disable 612, 618
+            modelBuilder
+                .HasAnnotation("ProductVersion", "7.0.4")
+                .HasAnnotation("Relational:MaxIdentifierLength", 128);
+
+            SqlServerModelBuilderExtensions.UseIdentityColumns(modelBuilder);
+
+            modelBuilder.Entity("ComputerStoreDatabaseImplement.Models.Component", b =>
+                {
+                    b.Property<int>("ID")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("int");
+
+                    SqlServerPropertyBuilderExtensions.UseIdentityColumn(b.Property<int>("ID"));
+
+                    b.Property<string>("Name")
+                        .IsRequired()
+                        .HasColumnType("nvarchar(max)");
+
+                    b.Property<double>("Price")
+                        .HasColumnType("float");
+
+                    b.HasKey("ID");
+
+                    b.ToTable("Components");
+                });
+
+            modelBuilder.Entity("ComputerStoreDatabaseImplement.Models.Consignment", b =>
+                {
+                    b.Property<int>("ID")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("int");
+
+                    SqlServerPropertyBuilderExtensions.UseIdentityColumn(b.Property<int>("ID"));
+
+                    b.Property<int>("OrderID")
+                        .HasColumnType("int");
+
+                    b.Property<double>("Price")
+                        .HasColumnType("float");
+
+                    b.Property<int?>("ProductID")
+                        .HasColumnType("int");
+
+                    b.HasKey("ID");
+
+                    b.HasIndex("OrderID");
+
+                    b.HasIndex("ProductID");
+
+                    b.ToTable("Consignments");
+                });
+
+            modelBuilder.Entity("ComputerStoreDatabaseImplement.Models.ConsignmentProduct", b =>
+                {
+                    b.Property<int>("ID")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("int");
+
+                    SqlServerPropertyBuilderExtensions.UseIdentityColumn(b.Property<int>("ID"));
+
+                    b.Property<int>("ConsignmentID")
+                        .HasColumnType("int");
+
+                    b.Property<int>("Count")
+                        .HasColumnType("int");
+
+                    b.Property<int>("ProductID")
+                        .HasColumnType("int");
+
+                    b.HasKey("ID");
+
+                    b.HasIndex("ConsignmentID");
+
+                    b.HasIndex("ProductID");
+
+                    b.ToTable("ConsignmentProducts");
+                });
+
+            modelBuilder.Entity("ComputerStoreDatabaseImplement.Models.Employee", b =>
+                {
+                    b.Property<int>("ID")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("int");
+
+                    SqlServerPropertyBuilderExtensions.UseIdentityColumn(b.Property<int>("ID"));
+
+                    b.Property<string>("FirstName")
+                        .HasColumnType("nvarchar(max)");
+
+                    b.Property<string>("LastName")
+                        .HasColumnType("nvarchar(max)");
+
+                    b.Property<string>("MiddleName")
+                        .HasColumnType("nvarchar(max)");
+
+                    b.Property<string>("Password")
+                        .IsRequired()
+                        .HasColumnType("nvarchar(max)");
+
+                    b.Property<string>("Username")
+                        .IsRequired()
+                        .HasColumnType("nvarchar(max)");
+
+                    b.HasKey("ID");
+
+                    b.ToTable("Employees");
+                });
+
+            modelBuilder.Entity("ComputerStoreDatabaseImplement.Models.Order", b =>
+                {
+                    b.Property<int>("ID")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("int");
+
+                    SqlServerPropertyBuilderExtensions.UseIdentityColumn(b.Property<int>("ID"));
+
+                    b.Property<DateTime>("DateCreate")
+                        .HasColumnType("datetime2");
+
+                    b.Property<DateTime?>("DateImplement")
+                        .HasColumnType("datetime2");
+
+                    b.Property<double>("Price")
+                        .HasColumnType("float");
+
+                    b.Property<int>("SellerID")
+                        .HasColumnType("int");
+
+                    b.Property<int>("Status")
+                        .HasColumnType("int");
+
+                    b.HasKey("ID");
+
+                    b.HasIndex("SellerID");
+
+                    b.ToTable("Orders");
+                });
+
+            modelBuilder.Entity("ComputerStoreDatabaseImplement.Models.PC", b =>
+                {
+                    b.Property<int>("ID")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("int");
+
+                    SqlServerPropertyBuilderExtensions.UseIdentityColumn(b.Property<int>("ID"));
+
+                    b.Property<int>("EmployeeID")
+                        .HasColumnType("int");
+
+                    b.Property<string>("Name")
+                        .IsRequired()
+                        .HasColumnType("nvarchar(max)");
+
+                    b.Property<double>("Price")
+                        .HasColumnType("float");
+
+                    b.Property<int>("RequestID")
+                        .HasColumnType("int");
+
+                    b.HasKey("ID");
+
+                    b.HasIndex("EmployeeID");
+
+                    b.ToTable("PCs");
+                });
+
+            modelBuilder.Entity("ComputerStoreDatabaseImplement.Models.Product", b =>
+                {
+                    b.Property<int>("ID")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("int");
+
+                    SqlServerPropertyBuilderExtensions.UseIdentityColumn(b.Property<int>("ID"));
+
+                    b.Property<int>("EmployeeID")
+                        .HasColumnType("int");
+
+                    b.Property<string>("Name")
+                        .IsRequired()
+                        .HasColumnType("nvarchar(max)");
+
+                    b.Property<double>("Price")
+                        .HasColumnType("float");
+
+                    b.HasKey("ID");
+
+                    b.HasIndex("EmployeeID");
+
+                    b.ToTable("Products");
+                });
+
+            modelBuilder.Entity("ComputerStoreDatabaseImplement.Models.ProductComponent", b =>
+                {
+                    b.Property<int>("ID")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("int");
+
+                    SqlServerPropertyBuilderExtensions.UseIdentityColumn(b.Property<int>("ID"));
+
+                    b.Property<int>("ComponentID")
+                        .HasColumnType("int");
+
+                    b.Property<int>("Count")
+                        .HasColumnType("int");
+
+                    b.Property<int>("ProductID")
+                        .HasColumnType("int");
+
+                    b.HasKey("ID");
+
+                    b.HasIndex("ComponentID");
+
+                    b.HasIndex("ProductID");
+
+                    b.ToTable("ProductComponents");
+                });
+
+            modelBuilder.Entity("ComputerStoreDatabaseImplement.Models.Request", b =>
+                {
+                    b.Property<int>("ID")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("int");
+
+                    SqlServerPropertyBuilderExtensions.UseIdentityColumn(b.Property<int>("ID"));
+
+                    b.Property<int>("OrderID")
+                        .HasColumnType("int");
+
+                    b.Property<int?>("PCID")
+                        .HasColumnType("int");
+
+                    b.Property<double>("Price")
+                        .HasColumnType("float");
+
+                    b.HasKey("ID");
+
+                    b.HasIndex("OrderID");
+
+                    b.ToTable("Requests");
+                });
+
+            modelBuilder.Entity("ComputerStoreDatabaseImplement.Models.RequestComponent", b =>
+                {
+                    b.Property<int>("ID")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("int");
+
+                    SqlServerPropertyBuilderExtensions.UseIdentityColumn(b.Property<int>("ID"));
+
+                    b.Property<int>("ComponentID")
+                        .HasColumnType("int");
+
+                    b.Property<int>("Count")
+                        .HasColumnType("int");
+
+                    b.Property<int?>("PCID")
+                        .HasColumnType("int");
+
+                    b.Property<int>("RequestID")
+                        .HasColumnType("int");
+
+                    b.HasKey("ID");
+
+                    b.HasIndex("ComponentID");
+
+                    b.HasIndex("PCID");
+
+                    b.HasIndex("RequestID");
+
+                    b.ToTable("RequestComponents");
+                });
+
+            modelBuilder.Entity("ComputerStoreDatabaseImplement.Models.Seller", b =>
+                {
+                    b.Property<int>("ID")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("int");
+
+                    SqlServerPropertyBuilderExtensions.UseIdentityColumn(b.Property<int>("ID"));
+
+                    b.Property<string>("FirstName")
+                        .HasColumnType("nvarchar(max)");
+
+                    b.Property<string>("LastName")
+                        .HasColumnType("nvarchar(max)");
+
+                    b.Property<string>("MiddleName")
+                        .HasColumnType("nvarchar(max)");
+
+                    b.Property<string>("Password")
+                        .IsRequired()
+                        .HasColumnType("nvarchar(max)");
+
+                    b.Property<string>("Username")
+                        .IsRequired()
+                        .HasColumnType("nvarchar(max)");
+
+                    b.HasKey("ID");
+
+                    b.ToTable("Sellers");
+                });
+
+            modelBuilder.Entity("ComputerStoreDatabaseImplement.Models.Consignment", b =>
+                {
+                    b.HasOne("ComputerStoreDatabaseImplement.Models.Order", "Order")
+                        .WithMany("_consignments")
+                        .HasForeignKey("OrderID")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.HasOne("ComputerStoreDatabaseImplement.Models.Product", null)
+                        .WithMany("Consignments")
+                        .HasForeignKey("ProductID");
+
+                    b.Navigation("Order");
+                });
+
+            modelBuilder.Entity("ComputerStoreDatabaseImplement.Models.ConsignmentProduct", b =>
+                {
+                    b.HasOne("ComputerStoreDatabaseImplement.Models.Consignment", "Consignment")
+                        .WithMany("Products")
+                        .HasForeignKey("ConsignmentID")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.HasOne("ComputerStoreDatabaseImplement.Models.Product", "Product")
+                        .WithMany()
+                        .HasForeignKey("ProductID")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("Consignment");
+
+                    b.Navigation("Product");
+                });
+
+            modelBuilder.Entity("ComputerStoreDatabaseImplement.Models.Order", b =>
+                {
+                    b.HasOne("ComputerStoreDatabaseImplement.Models.Seller", "Seller")
+                        .WithMany("Orders")
+                        .HasForeignKey("SellerID")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("Seller");
+                });
+
+            modelBuilder.Entity("ComputerStoreDatabaseImplement.Models.PC", b =>
+                {
+                    b.HasOne("ComputerStoreDatabaseImplement.Models.Employee", "Employee")
+                        .WithMany("PCs")
+                        .HasForeignKey("EmployeeID")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("Employee");
+                });
+
+            modelBuilder.Entity("ComputerStoreDatabaseImplement.Models.Product", b =>
+                {
+                    b.HasOne("ComputerStoreDatabaseImplement.Models.Employee", "Employee")
+                        .WithMany("Products")
+                        .HasForeignKey("EmployeeID")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("Employee");
+                });
+
+            modelBuilder.Entity("ComputerStoreDatabaseImplement.Models.ProductComponent", b =>
+                {
+                    b.HasOne("ComputerStoreDatabaseImplement.Models.Component", "Component")
+                        .WithMany("ConsignmentComponents")
+                        .HasForeignKey("ComponentID")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.HasOne("ComputerStoreDatabaseImplement.Models.Product", "Product")
+                        .WithMany("Components")
+                        .HasForeignKey("ProductID")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("Component");
+
+                    b.Navigation("Product");
+                });
+
+            modelBuilder.Entity("ComputerStoreDatabaseImplement.Models.Request", b =>
+                {
+                    b.HasOne("ComputerStoreDatabaseImplement.Models.Order", "Order")
+                        .WithMany("_requests")
+                        .HasForeignKey("OrderID")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("Order");
+                });
+
+            modelBuilder.Entity("ComputerStoreDatabaseImplement.Models.RequestComponent", b =>
+                {
+                    b.HasOne("ComputerStoreDatabaseImplement.Models.Component", "Component")
+                        .WithMany("RequestComponents")
+                        .HasForeignKey("ComponentID")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.HasOne("ComputerStoreDatabaseImplement.Models.PC", "PC")
+                        .WithMany("Components")
+                        .HasForeignKey("PCID");
+
+                    b.HasOne("ComputerStoreDatabaseImplement.Models.Request", "Request")
+                        .WithMany("PCs")
+                        .HasForeignKey("RequestID")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired();
+
+                    b.Navigation("Component");
+
+                    b.Navigation("PC");
+
+                    b.Navigation("Request");
+                });
+
+            modelBuilder.Entity("ComputerStoreDatabaseImplement.Models.Component", b =>
+                {
+                    b.Navigation("ConsignmentComponents");
+
+                    b.Navigation("RequestComponents");
+                });
+
+            modelBuilder.Entity("ComputerStoreDatabaseImplement.Models.Consignment", b =>
+                {
+                    b.Navigation("Products");
+                });
+
+            modelBuilder.Entity("ComputerStoreDatabaseImplement.Models.Employee", b =>
+                {
+                    b.Navigation("PCs");
+
+                    b.Navigation("Products");
+                });
+
+            modelBuilder.Entity("ComputerStoreDatabaseImplement.Models.Order", b =>
+                {
+                    b.Navigation("_consignments");
+
+                    b.Navigation("_requests");
+                });
+
+            modelBuilder.Entity("ComputerStoreDatabaseImplement.Models.PC", b =>
+                {
+                    b.Navigation("Components");
+                });
+
+            modelBuilder.Entity("ComputerStoreDatabaseImplement.Models.Product", b =>
+                {
+                    b.Navigation("Components");
+
+                    b.Navigation("Consignments");
+                });
+
+            modelBuilder.Entity("ComputerStoreDatabaseImplement.Models.Request", b =>
+                {
+                    b.Navigation("PCs");
+                });
+
+            modelBuilder.Entity("ComputerStoreDatabaseImplement.Models.Seller", b =>
+                {
+                    b.Navigation("Orders");
+                });
+#pragma warning restore 612, 618
+        }
+    }
+}
diff --git a/ComputerStoreDatabaseImplement/Migrations/20230517142400_RelationFixes.cs b/ComputerStoreDatabaseImplement/Migrations/20230517142400_RelationFixes.cs
new file mode 100644
index 0000000..aa17968
--- /dev/null
+++ b/ComputerStoreDatabaseImplement/Migrations/20230517142400_RelationFixes.cs
@@ -0,0 +1,112 @@
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace ComputerStoreDatabaseImplement.Migrations
+{
+    /// <inheritdoc />
+    public partial class RelationFixes : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropForeignKey(
+                name: "FK_Orders_Sellers_OrderID",
+                table: "Orders");
+
+            migrationBuilder.DropForeignKey(
+                name: "FK_RequestComponents_PCs_PCID",
+                table: "RequestComponents");
+
+            migrationBuilder.DropIndex(
+                name: "IX_Orders_OrderID",
+                table: "Orders");
+
+            migrationBuilder.DropColumn(
+                name: "OrderID",
+                table: "Orders");
+
+            migrationBuilder.AlterColumn<int>(
+                name: "PCID",
+                table: "RequestComponents",
+                type: "int",
+                nullable: true,
+                oldClrType: typeof(int),
+                oldType: "int");
+
+            migrationBuilder.CreateIndex(
+                name: "IX_Orders_SellerID",
+                table: "Orders",
+                column: "SellerID");
+
+            migrationBuilder.AddForeignKey(
+                name: "FK_Orders_Sellers_SellerID",
+                table: "Orders",
+                column: "SellerID",
+                principalTable: "Sellers",
+                principalColumn: "ID",
+                onDelete: ReferentialAction.Cascade);
+
+            migrationBuilder.AddForeignKey(
+                name: "FK_RequestComponents_PCs_PCID",
+                table: "RequestComponents",
+                column: "PCID",
+                principalTable: "PCs",
+                principalColumn: "ID");
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropForeignKey(
+                name: "FK_Orders_Sellers_SellerID",
+                table: "Orders");
+
+            migrationBuilder.DropForeignKey(
+                name: "FK_RequestComponents_PCs_PCID",
+                table: "RequestComponents");
+
+            migrationBuilder.DropIndex(
+                name: "IX_Orders_SellerID",
+                table: "Orders");
+
+            migrationBuilder.AlterColumn<int>(
+                name: "PCID",
+                table: "RequestComponents",
+                type: "int",
+                nullable: false,
+                defaultValue: 0,
+                oldClrType: typeof(int),
+                oldType: "int",
+                oldNullable: true);
+
+            migrationBuilder.AddColumn<int>(
+                name: "OrderID",
+                table: "Orders",
+                type: "int",
+                nullable: false,
+                defaultValue: 0);
+
+            migrationBuilder.CreateIndex(
+                name: "IX_Orders_OrderID",
+                table: "Orders",
+                column: "OrderID");
+
+            migrationBuilder.AddForeignKey(
+                name: "FK_Orders_Sellers_OrderID",
+                table: "Orders",
+                column: "OrderID",
+                principalTable: "Sellers",
+                principalColumn: "ID",
+                onDelete: ReferentialAction.Cascade);
+
+            migrationBuilder.AddForeignKey(
+                name: "FK_RequestComponents_PCs_PCID",
+                table: "RequestComponents",
+                column: "PCID",
+                principalTable: "PCs",
+                principalColumn: "ID",
+                onDelete: ReferentialAction.Cascade);
+        }
+    }
+}
diff --git a/ComputerStoreDatabaseImplement/Migrations/ComputerStoreDatabaseModelSnapshot.cs b/ComputerStoreDatabaseImplement/Migrations/ComputerStoreDatabaseModelSnapshot.cs
index 09a4479..f6b3b2d 100644
--- a/ComputerStoreDatabaseImplement/Migrations/ComputerStoreDatabaseModelSnapshot.cs
+++ b/ComputerStoreDatabaseImplement/Migrations/ComputerStoreDatabaseModelSnapshot.cs
@@ -138,9 +138,6 @@ namespace ComputerStoreDatabaseImplement.Migrations
                     b.Property<DateTime?>("DateImplement")
                         .HasColumnType("datetime2");
 
-                    b.Property<int>("OrderID")
-                        .HasColumnType("int");
-
                     b.Property<double>("Price")
                         .HasColumnType("float");
 
@@ -152,7 +149,7 @@ namespace ComputerStoreDatabaseImplement.Migrations
 
                     b.HasKey("ID");
 
-                    b.HasIndex("OrderID");
+                    b.HasIndex("SellerID");
 
                     b.ToTable("Orders");
                 });
@@ -274,7 +271,7 @@ namespace ComputerStoreDatabaseImplement.Migrations
                     b.Property<int>("Count")
                         .HasColumnType("int");
 
-                    b.Property<int>("PCID")
+                    b.Property<int?>("PCID")
                         .HasColumnType("int");
 
                     b.Property<int>("RequestID")
@@ -359,7 +356,7 @@ namespace ComputerStoreDatabaseImplement.Migrations
                 {
                     b.HasOne("ComputerStoreDatabaseImplement.Models.Seller", "Seller")
                         .WithMany("Orders")
-                        .HasForeignKey("OrderID")
+                        .HasForeignKey("SellerID")
                         .OnDelete(DeleteBehavior.Cascade)
                         .IsRequired();
 
@@ -428,9 +425,7 @@ namespace ComputerStoreDatabaseImplement.Migrations
 
                     b.HasOne("ComputerStoreDatabaseImplement.Models.PC", "PC")
                         .WithMany("Components")
-                        .HasForeignKey("PCID")
-                        .OnDelete(DeleteBehavior.Cascade)
-                        .IsRequired();
+                        .HasForeignKey("PCID");
 
                     b.HasOne("ComputerStoreDatabaseImplement.Models.Request", "Request")
                         .WithMany("PCs")
diff --git a/ComputerStoreDatabaseImplement/Models/PC.cs b/ComputerStoreDatabaseImplement/Models/PC.cs
index 56d6eea..704c246 100644
--- a/ComputerStoreDatabaseImplement/Models/PC.cs
+++ b/ComputerStoreDatabaseImplement/Models/PC.cs
@@ -87,12 +87,16 @@ namespace ComputerStoreDatabaseImplement.Models
             var pcComponents = context.RequestComponents.Where(rec => rec.PCID == model.ID && rec.RequestID == model.RequestID).ToList();
             if(pcComponents != null &&  pcComponents.Count > 0)
             {
-                context.RequestComponents.RemoveRange(pcComponents.Where(rec => !model.PCComponents.ContainsKey(rec.ComponentID) && rec.RequestID == model.RequestID));
-                context.SaveChanges();
+                if(pcComponents.Where(rec => !model.PCComponents.ContainsKey(rec.ComponentID) && rec.RequestID == model.RequestID).Any())
+                {
+                    context.RequestComponents.RemoveRange(pcComponents.Where(rec => !model.PCComponents.ContainsKey(rec.ComponentID) && rec.RequestID == model.RequestID));
+                    context.SaveChanges();
+                }
+               
                 foreach(var updateComponent  in pcComponents)
                 {
-                    updateComponent.Count = model.PCComponents[updateComponent.PCID].Item2;
-                    model.PCComponents.Remove(updateComponent.PCID);
+                    updateComponent.Count = model.PCComponents[updateComponent.ComponentID].Item2;
+                    model.PCComponents.Remove(updateComponent.ComponentID);
                 }
                 context.SaveChanges();
             }
diff --git a/ComputerStoreDatabaseImplement/Models/Product.cs b/ComputerStoreDatabaseImplement/Models/Product.cs
index a59a758..9369614 100644
--- a/ComputerStoreDatabaseImplement/Models/Product.cs
+++ b/ComputerStoreDatabaseImplement/Models/Product.cs
@@ -83,20 +83,23 @@ namespace ComputerStoreDatabaseImplement.Models
         public void UpdateComponents(ComputerStoreDatabase context, ProductBindingModel model)
         {
             var productComponents = context.ProductComponents.Where(rec => rec.ProductID == model.ID).ToList();
-            if(productComponents != null && productComponents.Count > 0)
+            if (productComponents != null && productComponents.Count > 0)
             {
-                context.ProductComponents.RemoveRange(productComponents.Where(rec => !model.ProductComponents.ContainsKey(rec.ComponentID)));
-                context.SaveChanges();
-                foreach(var updateComponent in productComponents)
+                if (productComponents.Where(rec => !model.ProductComponents.ContainsKey(rec.ComponentID)).Any())
                 {
-                    updateComponent.Count = model.ProductComponents[updateComponent.ID].Item2;
-                    model.ProductComponents.Remove(updateComponent.ID);
+                    context.ProductComponents.RemoveRange(productComponents.Where(rec => !model.ProductComponents.ContainsKey(rec.ComponentID)));
+                    context.SaveChanges();
+                }
+                foreach (var updateComponent in productComponents.Where(x => model.ProductComponents.ContainsKey(x.ComponentID)))
+                {
+                    updateComponent.Count = model.ProductComponents[updateComponent.ComponentID].Item2;
+                    model.ProductComponents.Remove(updateComponent.ComponentID);
                 }
                 context.SaveChanges();
             }
 
             var product = context.Products.First(x => x.ID == ID);
-            foreach(var pc in model.ProductComponents)
+            foreach (var pc in model.ProductComponents)
             {
                 context.ProductComponents.Add(new ProductComponent
                 {
diff --git a/ComputerStoreDatabaseImplement/Models/RequestComponent.cs b/ComputerStoreDatabaseImplement/Models/RequestComponent.cs
index 3157632..3e54ed0 100644
--- a/ComputerStoreDatabaseImplement/Models/RequestComponent.cs
+++ b/ComputerStoreDatabaseImplement/Models/RequestComponent.cs
@@ -17,13 +17,13 @@ namespace ComputerStoreDatabaseImplement.Models
         [Required]
         public int ComponentID { get; set; }
 
-        [Required]
-        public int PCID { get; set; }
+        
+        public int? PCID { get; set; }
 
         [Required]
         public int Count { get; set; }
 
-        public virtual PC PC { get; set; } = new();
+        public virtual PC? PC { get; set; } = new();
         public virtual Component Component { get; set; } = new();
         public virtual Request Request { get; set; } = new();
     }
diff --git a/ComputerStoreDatabaseImplement/Models/Seller.cs b/ComputerStoreDatabaseImplement/Models/Seller.cs
index a48e66a..fda93c5 100644
--- a/ComputerStoreDatabaseImplement/Models/Seller.cs
+++ b/ComputerStoreDatabaseImplement/Models/Seller.cs
@@ -23,7 +23,7 @@ namespace ComputerStoreDatabaseImplement.Models
         public string? LastName { get; private set; } = string.Empty;
         public string? MiddleName { get; private set; } = string.Empty;
 
-        [ForeignKey("OrderID")]
+        [ForeignKey("SellerID")]
         public virtual List<Order> Orders { get; set; } = new();
 
         public static Seller? Create(SellerBindingModel? model)