单向一对多，父级具有复合密钥

Question

I need to create a one to many mapping between a parent and child. Parent has an embedded id. I took this approach and I get:

EDIT: The parent table contains 3 columns, which are foreign keys from 3 different Child tables.

org.hibernate.AnnotationException: A Foreign key refering com.Parent from com.Child has the
wrong number of column. should be 3

Parent {
    @EmbeddedId
    private ParentEmbeddedId id;

    @OneToMany(fetch = FetchType.EAGER)
    @JoinTable(name = "Child",
               joinColumns = {
                   @JoinColumn(name="childId2"),
                   @JoinColumn(name="childId3")
               },
               inverseJoinColumns={
                   @JoinColumn(name="childId1")
               })
    private Collection<Child> children;

}

ParentEmbeddedId {
    private long childId1;
    private long childId2;
    private long childId3;
}

Child {
    private long childId1;
}

2nd approach:

Using the below mapping also gives the same above exception:

@OneToMany
@JoinColumn(name = "childId1")
private Collection<Child> children;

3rd approach:

@OneToMany
@JoinColumns({
    @JoinColumn(name="childId1", referencedColumnName="childId1"),
    @JoinColumn(name="childId2", referencedColumnName="childId2"),
    @JoinColumn(name="childId3", referencedColumnName="childId3"),
})
private Collection<Child> Children

This causes

java.sql.SQLSyntaxErrorException: ORA-00904: "Child2_"."childId3": invalid identifier;

Basically, the query generated by hibernate is trying to run query using "childId3" column that does not exist in "Child" table.

Answer 1

Try with

 Child {
    private long childId1;
    private long childId2;
    private long childId3;
}