Child List collection deletion woes

rollatwork · **Posted:** Wed Jun 02, 2004 12:26 am

We have a child collection which is mapped as a one-to-many List:

Code:

<list name="children" 
    table="CHILDREN" 
    lazy="true" 
    cascade="all-delete-orphan">
        <key column="parent_id"/>
        <index column="I"/>
        <one-to-many class="Child"/>
</list>

The Child entity has a many-to-one reference to the Parent entity and has a not-null value set to true. We are aware that when using Lists, a mandatory requirement for this collection because the index is important to our domain, you cannot use inverse relationships.

We have read the parent/child documentation and have applied in many other areas with success. However, currently we are experiencing deletion issues when trying to remove all the collections, which is of type List, from the parent.

Currently, we are doing it in this way:

Code:

...
p.getChildren().remove(child);
session.delete(child);
...

We have a foreign key constraint on the child table to the parent table.

Our exception upon deletion is:

Code:

java.sql.SQLException: Cannot insert the value NULL into column... column does not allow nulls

As already mentioned we are using a List and we are aware we cannot use inverse="true". Also, we have attempted setting cascade="all-delete-orphan" without any success. In fact, it produces the same error message.

Question

Our use case requires that we be able to delete this collection of children. Can anyone see any glaring issues with the way we are attempting to delete collections?

We have tried several different mapping and deletion idioms suggested in this forum and in the ref documentation.

Additional Information

Hibernate 2.1.3
MS SQL Server 2000
New Atlanta JTurbo Driver 0.7.1

Cheers,
Roll

anthony · **Posted:** Wed Jun 02, 2004 7:40 am

have you understood all this:
http://www.hibernate.org/hib_docs/refer ... child.html ?

rollatwork · **Posted:** Wed Jun 02, 2004 8:35 am

Yes, we've read it on many occassions. Possibly our interpretation is incorrect.

Based on your understanding, does anything jump out at you from the original post?

Doc you point to discusses deletion lifecycle in parent child relationships using bi-directional one-to-many mapping. We're using a List where you cannot specify inverse=true and have attempted to employ various techniques from this very doc.

Cheers,
Roll

rollatwork · **Posted:** Wed Jun 02, 2004 3:35 pm

We are well aware of the following from the docs:

Quote:

Very Important Note: If the <key> column of a <one-to-many> association is declared NOT NULL, Hibernate may cause constraint violations when it creates or updates the association. To prevent this problem, you must use a bidirectional association with the many valued end (the set or bag) marked as inverse="true". See the discussion of bidirectional associations later in this chapter.

Our issue is that we have a requirement for an indexed one-to-many collection in our entity, which is why we chose List, and when we try to delete children in this collection a constraint violation is thrown.

Is there a way, other than bidirectional assocation which we cannot use with Lists, to get around this issue?

Cheers,
Roll