Lab 3

src/main/java/ru/ulstu/is/cbapp/models/StudentCategory.java

@@ -0,0 +1,30 @@
+package ru.ulstu.is.cbapp.models;
+
+import javax.persistence.*;
+
+@Entity
+@Table(name = "StudentCategory")
+public class StudentCategory {
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Long id;
+
+    @ManyToOne
+    private Student student;
+
+    @ManyToOne
+    private Category category;
+
+    public StudentCategory(Student student, Category Category) {
+        this.student = student;
+        this.category = category;
+    }
+
+    public StudentCategory() {
+    }
+
+    public Long getId() {
+        return id;
+    }
+
+}

src/main/java/ru/ulstu/is/cbapp/service/DrivingSchoolService.java

@@ -3,13 +3,19 @@ package ru.ulstu.is.cbapp.service;
 import javax.persistence.EntityManager;
 import javax.persistence.EntityNotFoundException;
 import javax.persistence.PersistenceContext;
+import javax.persistence.TypedQuery;
+
+import org.springframework.data.util.Pair;
 import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
 import org.springframework.util.StringUtils;
+import ru.ulstu.is.cbapp.models.Category;
 import ru.ulstu.is.cbapp.models.DrivingSchool;
 import ru.ulstu.is.cbapp.models.Student;
 
+import java.util.ArrayList;
 import java.util.List;
+import java.util.Objects;
 
 @Service
 public class DrivingSchoolService {
@@ -82,6 +88,28 @@ public class DrivingSchoolService {
         em.merge(currentDrivingSchool);
     }
 
+    @Transactional
+    public List<Pair<Long, Integer>> CountStudentsCategory(Long dsID) {
+        TypedQuery<Object[]> query = em.createQuery("SELECT sc.category.Id, COUNT(sc.category.Id) AS count " +
+                        "FROM StudentCategory sc " +
+                        "JOIN sc.student s " +
+                        "JOIN s.drivingSchool ds " +
+                        "WHERE ds.Id=:dsID " +
+                        "GROUP BY sc.category.Id", Object[].class)
+                .setParameter("dsID", dsID);
+
+        List<Object[]> resultList = query.getResultList();
+        List<Pair<Long, Integer>> pairs = new ArrayList<>();
+
+        for (Object[] result : resultList) {
+            Long categoryId = (Long) result[0];
+            Integer count = ((Number) result[1]).intValue();
+            Pair<Long, Integer> pair = Pair.of(categoryId, count);
+            pairs.add(pair);
+        }
+        return pairs;
+    }
+
     @Transactional
     public void addAllStudent(Long id, List<Student> students) {
         DrivingSchool currentDrivingSchool = findDrivingSchool(id);

src/main/resources/application.properties

@@ -1,5 +1,5 @@
 spring.main.banner-mode=off
-#server.port=8080
+server.port=8080
 spring.datasource.url=jdbc:h2:file:./data
 spring.datasource.driverClassName=org.h2.Driver
 spring.datasource.username=sa

src/test/java/ru/ulstu/is/cbapp/DrivingSchoolServiceTests.java

@@ -5,8 +5,11 @@ import org.junit.jupiter.api.Assertions;
 import org.junit.jupiter.api.Test;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.data.util.Pair;
+import ru.ulstu.is.cbapp.models.Category;
 import ru.ulstu.is.cbapp.models.DrivingSchool;
 import ru.ulstu.is.cbapp.models.Student;
+import ru.ulstu.is.cbapp.service.CategoryService;
 import ru.ulstu.is.cbapp.service.DrivingSchoolService;
 import ru.ulstu.is.cbapp.service.StudentService;
 
@@ -17,7 +20,8 @@ import java.util.List;
 public class DrivingSchoolServiceTests {
     @Autowired
     private DrivingSchoolService drivingSchoolService;
-
+    @Autowired
+    private CategoryService categoryService;
     @Autowired
     private StudentService studentService;
 
@@ -78,6 +82,43 @@ public class DrivingSchoolServiceTests {
         drivingSchoolService.deleteAllDrivingSchools();
     }
 
+    @Test
+    public void testGroupStudentCategory() {
+        studentService.deleteAllStudents();
+        drivingSchoolService.deleteAllDrivingSchools();
+        categoryService.deleteAllCategories();
+
+        final String name = "DrivingSchool";
+        DrivingSchool d = drivingSchoolService.addDrivingSchool(name);
+
+        Student s1 = studentService.addStudent("cha", "chacha", "111");
+        Student s2 = studentService.addStudent("cha", "chacha", "111");
+        Student s3 = studentService.addStudent("cha", "chacha", "111");
+
+        Category c1 = categoryService.addCategory("Category1");
+        Category c2 = categoryService.addCategory("Category2");
+        Category c3 = categoryService.addCategory("Category3");
+
+        studentService.addCategory(s1.getId(), c1);
+        studentService.addCategory(s2.getId(), c2);
+        studentService.addCategory(s3.getId(), c3);
+
+        List<Student> studs = new ArrayList<>();
+        studs.add(s1);
+        studs.add(s2);
+        studs.add(s3);
+
+        drivingSchoolService.addAllStudent(d.getId(), studs);
+
+        List<Pair<Long,Integer>> list=drivingSchoolService.CountStudentsCategory(d.getId());
+
+        Assertions.assertNotNull(list);
+
+        studentService.deleteAllStudents();
+        drivingSchoolService.deleteAllDrivingSchools();
+        categoryService.deleteAllCategories();
+    }
+
     @Test
     public void testAddStudent() {
 
@@ -91,6 +132,7 @@ public class DrivingSchoolServiceTests {
         Student s2 = studentService.addStudent("cha", "chacha", "111");
         Student s3 = studentService.addStudent("cha", "chacha", "111");
 
+
         List<Student> studs = new ArrayList<>();
         studs.add(s1);
         studs.add(s2);