Have JPA/Hibernate to replicate the “ON DELETE SET NULL” functionality

Question

I\'ve been able to have JPA/Hibernate to replicate the ON DELETE CASCADE functionality successfully (seems like the default behaviour) but I\'m now trying to re

Answer 1

It doesn't appear to be possible at the moment with jpa/hibernate.

On delete set null in hibernate in @OneToMany

JBs solution seems clean though:

for (Department child : parent.getChildren()) {
    child.setParentDepartment(null);
}
session.delete(parent);

You should also be able to put it in a PreRemove:

@PreRemove
private void preRemove() {
    for (Student s : studentList) {
        s.setTeacher(null);
    }
}

Answer 2

What about defining

@ForeignKey(name = "fk_student_teacher",
            foreignKeyDefinition = " /*FOREIGN KEY in sql that sets ON DELETE SET NULL*/")

?

Answer 3

I think that the best solution is a user SQL statement for setting on delete action as follow:

CREATE TABLE table_name
(
  column1 datatype null/not null,
  column2 datatype null/not null,
  ...

  CONSTRAINT fk_column
     FOREIGN KEY (column1, column2, ... column_n)
     REFERENCES parent_table (column1, column2, ... column_n)
     ON DELETE SET NULL
);

when user deletes a row by other cascading delete where you use a table reference to this deleted row, you could not use hibernate solution and return SQL exception.