"FK_63a66b22ace64374a874912be64". Конфликт произошел в базе данных "ForHiberTest", таблица "dbo.prepod_Student", column 'students_id'.

@Entity
@Table(name = "prepod")
public class Prepod {

    private Long id;
    private String name;
    @Column
    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    List<Student> students = new ArrayList<Student>();

    @ManyToMany(fetch=FetchType.EAGER)
    public List<Student> getStudents() {
        return students;
    }

    public void setStudents(List<Student> students) {
        this.students = students;
    }

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "id")
    public Long getId() {
        return id;
    }

    public void setId(Long i) {
        id = i;
    }
}

@Entity
@Table(name = "Student")
public class Student {

    private Long id;
    private String name;
    private Long age;
    private List<Prepod> prepods = new ArrayList<Prepod>();

    @ManyToMany(mappedBy = "students",fetch=FetchType.EAGER)
    public List<Prepod> getPrepods() {
        return prepods;
    }

    public void setPrepods(List<Prepod> prepods) {
        this.prepods = prepods;
    }

    public Student() {
        name = null;
    }

    public Student(Student s) {
        name = s.getName();
    }

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "id")
    public Long getId() {
        return id;
    }

    @Column(name = "name")
    public String getName() {
        return name;
    }

    @Column(name = "age")
    public Long getAge() {
        return age;
    }

    public void setId(Long i) {
        id = i;
    }

    public void setName(String s) {
        name = s;
    }

    public void setAge(Long age) {
        this.age = age;
    }
}

student.getPrepods().clear();