Fix: Delete Subject (#113)

* fix: path variable typo

* feat: add FetchType.EAGER

* feat: remove all students and teachers before deleting

src/main/java/com/electric_diary/controllers/SubjectController.java

@@ -45,8 +45,8 @@ public ResponseEntity<SubjectEntity> updateSubject(@PathVariable Integer subject
 	}
 
 	@DeleteMapping("/{subjectId}")
-	public ResponseEntity<SubjectEntity> deleteSubject(@PathVariable Integer subjectid) {
-		return new ResponseEntity<>(subjectService.deleteSubject(subjectid), HttpStatus.OK);
+	public ResponseEntity<SubjectEntity> deleteSubject(@PathVariable Integer subjectId) {
+		return new ResponseEntity<>(subjectService.deleteSubject(subjectId), HttpStatus.OK);
 	}
 
 	@PutMapping("/{subjectId}/students/{studentId}")

src/main/java/com/electric_diary/entities/SubjectEntity.java

@@ -6,6 +6,7 @@
 import com.fasterxml.jackson.annotation.JsonIgnore;
 
 import jakarta.persistence.Entity;
+import jakarta.persistence.FetchType;
 import jakarta.persistence.GeneratedValue;
 import jakarta.persistence.GenerationType;
 import jakarta.persistence.Id;
@@ -35,14 +36,14 @@ public class SubjectEntity {
 
 	@NotNull
 	@JsonIgnore
-	@OneToMany(mappedBy = "subject")
+	@OneToMany(mappedBy = "subject", fetch = FetchType.EAGER)
 	private Set<GradeEntity> grades = new HashSet<GradeEntity>();
 
-	@ManyToMany
+	@ManyToMany(fetch = FetchType.EAGER)
 	@JoinTable(name = "student_enrolled", joinColumns = @JoinColumn(name = "subject_id"), inverseJoinColumns = @JoinColumn(name = "student_id"))
 	private Set<StudentEntity> enrolledStudents = new HashSet<>();
 
-	@ManyToMany(mappedBy = "subjects")
+	@ManyToMany(mappedBy = "subjects", fetch = FetchType.EAGER)
 	private Set<TeacherEntity> teachers = new HashSet<>();
 
 	public void enrolStudents(StudentEntity student) {

src/main/java/com/electric_diary/services/impl/SubjectServiceImpl.java

@@ -7,6 +7,7 @@
 import com.electric_diary.DTO.Request.SubjectRequestDTO;
 import com.electric_diary.entities.StudentEntity;
 import com.electric_diary.entities.SubjectEntity;
+import com.electric_diary.entities.TeacherEntity;
 import com.electric_diary.exception.NotFoundException;
 import com.electric_diary.repositories.StudentRepository;
 import com.electric_diary.repositories.SubjectRepository;
@@ -68,6 +69,12 @@ public SubjectEntity updateSubject(Integer subjectId, SubjectRequestDTO subjectR
 	@Override
 	public SubjectEntity deleteSubject(Integer subjectId) {
 		SubjectEntity subject = getSubjectById(subjectId);
+		for (StudentEntity student : subject.getEnrolledStudents())
+			student.getSubjects().remove(subject);
+
+		for (TeacherEntity teacher : subject.getTeachers())
+			teacher.getSubjects().remove(subject);
+
 		subjectRepository.delete(subject);
 		logger.info("Deleted subject with ID {}.", subjectId);
 		return subject;