How to delete object references?

saiake · **Joined:** Mon Jan 22, 2007 10:16 am **Posts:** 5

Hi!

I've been having problems removing an object that has references to it. I've searched everywhere, but none of the solutions helped me. Maybe I didn't know what exactly to search for at all...

Here's the problem:

- Assume we have objects Foo and Bar.

- Foo contains a List of Bars.

Foo's mapping file is something like this:

Code:

<hibernate-mapping>
   <class name="Foo" table="Foo">

       <id name="id" column="PKEY">
             <generator class="identity"/>
       </id>
    
   <property name="name" column="Name" not-null="true" unique="true"/>
        
   <list name="bars" table="Foo_Bars" lazy="false">
      <key column="FK_Foo"/>
      <list-index column="SortOrder"/>
      <many-to-many column="FK_Bar" class="Bar"/>
   </list>
      
   </class>
</hibernate-mapping>

Bar's mapping file actually doesn't relate to the problem, assume its just a simple class with one string attribute or something.

No, when I try to delete the Bar, I get a REFERENCE contraint error, because Foo has references to Bar.
Yes, I could (manually) delete all the references to Bar in the relation table Foo_Bars, before deleting Bar itself, but I will have an unknown number of different objects pointing to the Bar the same way Foo does.

Is my Foo mapping file just plain wrong, or is this problem a very tough one?

passos · **Posted:** Tue Jan 30, 2007 5:18 pm

I think Hibernate dont only remove association.

If you add cascade in your mapping hibernate is try delete association and bars. If you dont add cascade hibernate delete only foo

saiake · **Joined:** Mon Jan 22, 2007 10:16 am **Posts:** 5

OK, I have solved my own problem.

All I needed to do was this:

Code:

 <list name="bars" table="Foo_Bars" cascade="delete-orphan" lazy="false">
      <key column="FK_Foo"/>
      <list-index column="SortOrder"/>
      <one-to-many class="Bar"/>
   </list> 