Hibernate @ManyToOne Cascade работает очень странно ⇐ JAVA

[Anonymous]

I have a project where every Student can be tested by a Tester, and a single tester can test many students.
I need students to know their testers - so this is a unidirectional Many to One.

Tester:

@Entity public class Tester { @Id @GeneratedValue(strategy = GenerationType.IDENTITY) private Long id; @Column(nullable = false) private String name; public Tester(String name) { this.name = name; } protected Tester(){} public String getName() { return this.name; } @Override public String toString() { return String.format("Tester [id=%s, name=%s]", this.id, this.name); } } Student:

@Entity public class Student { @Id private Long id; //this shouldn't be auto incremented @Column(nullable = false) private int age; @ManyToOne(cascade = CascadeType.PERSIST) @JoinColumn(name = "tester_id") private Tester tester; public Student(Long id, int age, Tester tester) { this.id = id; this.age = age; this.tester = tester; } protected Student(){} public int getAge() { return this.age; } public Tester getTester() { return this.tester; } @Override public String toString() { return String.format("Student [id=%s, age=%s, tester=%s]", this.id, this.age, this.tester); } } When I run this code:

Tester tester = new Tester("Tester"); Student student = new Student(1L, 27, tester); this.studentRepository.save(student); I expect both entities to be saved due to the cascade, but instead I get an sql error because the tester's name is magically null?!? If I remove the nullable = false from the column, the tester entity is saved but with null in the name column... What the hell did I do wrong?

Please don't recommend saving the Tester first, it's not helping because I want to understand what's wrong with my code.


Источник: https://stackoverflow.com/questions/780 ... er-weirdly