CODEWITHSUNDEEP
hibernatejpaspring-data
mstrom
mstrom

Reputation: 1743

Hibernate - Foreign key referring to wrong number of columns (one-to-many, many-to-one)

I'm new to Hibernate and JPA, so hopefully this is something basic. I'm getting an exception: "Foreign key referring Foo from Bar has the wrong number of columns". I'm not sure why. Any ideas? Thanks!

public abstract class Foo extends AbstractPersistable{

    @Id @GeneratedValue
    @Column(name = "FooId")
    private Long foo_id;

    @OneToMany(mappedBy= "foo")
    private Set<Bar> bars;
}

public abstract class Bar extends AbstractPersistable{
    @Id @GeneratedValue
    @Column(name = "BarId")
    private Long bar_id;

    @ManyToOne
    @JoinColumn(name = "FooId", nullable = false, insertable = false, updatable = false)
    private Foo foo;
}

Upvotes: 1

Views: 547

Answers (2)

mstrom
mstrom

Reputation: 1743

Turns out I was extending a class that already provided an Integer id. My id was of type Long, thus it was looking for two foreign keys.

Upvotes: 0

Jakub Kubrynski
Jakub Kubrynski

Reputation: 14149

Using @JoinColumn in such situation is redundant. Try such code:

public abstract class Foo extends AbstractPersistable{

  @Id @GeneratedValue
  @Column(name = "FooId")
  private Long foo_id;

  @OneToMany(mappedBy = "foo")
  private Set<Bar> bars;
}

public abstract class Bar extends AbstractPersistable{
  @Id @GeneratedValue
  @Column(name = "BarId")
  private Long bar_id;

  @ManyToOne
  private Foo foo;
}

Upvotes: 1

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