Error SQL Error: 1452, SQLState: 23000, using hibernate and javafx

Question

I'm getting this error when trying to save data into a table that contains foreign key columns.

This is my scenario I'm picking two options from two different ComboBoxes (one option from each different ComboBox), I write two strings, all this to build my object to save but when committing I get this error:

WARN SqlExceptionHelper - SQL Error: 1452, SQLState: 23000 ERROR SqlExceptionHelper - Cannot add or update a child row: a foreign key constraint fails (students.student, CONSTRAINT fk_student_career FOREIGN KEY (student_career) REFERENCES career (career_name) ON DELETE NO ACTION ON UPDATE NO ACTION) ERROR ExceptionMapperStandardImpl - HHH000346: Error during managed flush [org.hibernate.exception.ConstraintViolationException: could not execute statement]

These are my classes I placed them in my gists repositories to make this post a little bit short.

I have followed many tutorials and read a lot of info but can't manage to make it work. I have used the cascadetype, JoinColumn and many other things but failed in all...

Please help me...

P.S.: I'm self-learning and this a practice.

Answer 1

Change Student class mapping (I've included just the relevant part) to:

@Entity
@Table(name = "student", catalog = "students")
public class Student implements java.io.Serializable {

    ...

    @ManyToOne(fetch = FetchType.LAZY, cascade = CascadeType.PERSIST)
    @JoinColumn(name = "student_career",referencedColumnName="career_name" nullable = false)
    private Career career;

    @ManyToOne(fetch = FetchType.LAZY, cascade = CascadeType.PERSIST)
    @JoinColumn(name = "student_section", nullable = false)
    private Section section;

    ...
}

• referencedColumnName is used to explicitly map Career foreign key to the correct column career_name instead of its id career_id, check this related question for more detail.

• CascadeType.PERSIST was added to save both to Career and Section while saving Student, if not, the database won't find the appropriate record for Student's foreign keys, (and I think, this is the origin of the SqlExceptionHelper)