I am experiencing another behavior than described in the
Hibernate Annotations Reference Guide, so I am wondering if there is a mistake in the Reference Guide.

I try to map a Parent-Child association with a bidirectional list.
Since I am using a list, the parent has to be the owning side of the relationship (no "mappedBy" possible).
I want Hibernate to produce optimal SQL. I expect two SQL-inserts and no SQL-update when creating a new Parent with one new Child.

I am using Hibernate Annotations for the mapping.
The Hibernate Annotations Reference Guide (Chapter 2.4.6.2.3) suggests the following solution:

On the Parent:

On the Child:

But in this case Hibernate produces three SQL statements when persisting a parent with one child:


This is not the behavior that the Hibernate Annotations Reference Guide describes!


If I repeat the @JoinColumn attributes 'updatable = false' and 'insertable = false' from the Child to the Parent like this:

Then Hibernate produces the SQL I am expecting:


I am wondering: Is there a mistake in the The Hibernate Annotations Reference Guide (Chapter 2.4.6.2.3) ?
Has there been a change in a recent Hibernate release?
Or am I missing something?

See also this thread for a complete code example.

Hi,
Since parent table does not keep parent_id, you should not use @JoinColumn(name = "parent_id") in parent class.

Try to map like that and try to insert again.

Parent:
@OneToMany(cascade = CascadeType.ALL, fetch = FetchType.LAZY, mappedBy = "parent")
public List<Child> getChildren() {
return children;
}

Child
@ManyToOne(fetch = FetchType.LAZY)
@JoinColumn(name = "PARENT_ID")
public Parent getParent() {
return parent;
}

Ok, I was not reading the Annotations Reference Guide thoroughly enough.

In Chapter 2.2.5.3.2.1 it is stated clearly:



It probably would not hurt to repeat this information in Chapter 2.4.6.2.3.

Now the question remains: if I repeat the @JoinColumn attributes 'updatable = false' and 'insertable = false' on the Parent (see code in first post) the additional update statements seem not to get produced... is this a legitimate workaround? Or does this result in another problem?