ORA-02292 when using Hibernate

Question

I am trying to implement a delete function but all I get is this ORA-02292 ERROR:

Caused by: java.sql.SQLIntegrityConstraintViolationException: ORA-02292: Integritäts-Constraint (VDMA.FK892DE8B473F40868) verletzt - untergeordneter Datensatz gefunden

    at oracle.jdbc.driver.T4CTTIoer.processError(T4CTTIoer.java:447)
    at oracle.jdbc.driver.T4CTTIoer.processError(T4CTTIoer.java:396)
    at oracle.jdbc.driver.T4C8Oall.processError(T4C8Oall.java:951)

I have an Entity (MainEntity) that has an n:m relationship with its child entity.

For example: A User can have multiple cars, each car can be driven by different users.

When a User is deleted, I want the associations between the User and the Car to be deleted as well. That´s why I thought I could do the following :

User Entity

@ManyToMany(fetch = FetchType.LAZY, cascade = CascadeType.ALL)
@JoinTable(name = "user_car", joinColumns = {@JoinColumn(name = DATABASE_COLUMN_ID, nullable = false, updatable = false) }, inverseJoinColumns = {@JoinColumn(name = DATABASE_COLUMN_TYPE_ID,
      nullable = true, updatable = false) })
private Set<UserCar> userCars;

Car Entity

@ManyToMany(fetch = FetchType.LAZY, mappedBy = "userCars")
  private Set<User> users;

The result is :

The tables get created, the data gets persisted - everything works fine. EXCEPT deleting entries: As soon as I try to delete a User and the User has a car (and therefore a user : car relationship) I do get the errors shown above.

If the user doesn´t have any cars I can delete him without any issues. So the problem must be the constraint in the USER_CAR table.

Answer 1

Clear userCars as well:

user.getUserCars().clear()

This will break the association between user and associated cars (it will delete the corresponding records from the junction table).

Also, you don't want CascadeType.ALL on many-to-many associations, because it implicitly contains CascadeType.REMOVE. Using it means that removal will be cascaded to cars as well, although there are other users who are associated with those cars.