Mapping.Delete.Cascade?!

vadimv · **Joined:** Wed Oct 19, 2005 8:04 am **Posts:** 19

Suppose i have 2 tables, that are related:

One is Terminal table and has following mapping to another table called TerminalModel:

<many-to-one name="terminalModel" lazy="false"
class="TerminalModel"
column="termmodel_id"
cascade="none"/>

And happened that i need to delete a row from TerminalModel, but if i delete it is gone but termmodel_id in Terminal table stays same and i get an error while getting list of Terminals, since related object from TerminalModel with that ID doesn't exist anymore. So my question is, how can i delete object from table TerminalModel so it sets termmodel_id in parrent table Terminal to null but dont delete the whole row?

Thank u!

tenwit · **Joined:** Thu Dec 23, 2004 9:08 pm **Posts:** 2008

Code:

terminal.setTerminalModel(null);
session.delete(terminalModel);
session.flush();

vadimv · **Joined:** Wed Oct 19, 2005 8:04 am **Posts:** 19

That is too easy, but imagine i have 10000 Terminals, then i will have to get list of all those terminals that have that TerminalModel and run

Code:

terminal.setTerminalModel(null);

for every single terminal and that is insane to run it 10000 times...
There must be some easy way Hibernate manages it.
Any suggestions?

max · **Posted:** Fri Jul 28, 2006 7:28 am

welcome to pointer chasing ;)

This is the price you "pay" to be able to unittest your domainmodel without a "persistence container". Your code will work both with and without hibernate.

vadimv · **Joined:** Wed Oct 19, 2005 8:04 am **Posts:** 19

Didn't really understand what u did ment by that :P

max · **Posted:** Fri Jul 28, 2006 9:19 am

just telling you that hibernate does not mess with your associations and we do not do "container managed relationships".

If we did automatically do this you would not be able to use your domaincode in e.g. unittests without hibernate.

Plus what about other objects that is pointing to this object? Should hibernate load them all automatically and null them out ?

vadimv · **Joined:** Wed Oct 19, 2005 8:04 am **Posts:** 19

I just asked, cuz i am tottaly newb to Hibernate, so u don't have to blame me for not knowing such things.
But thanks anyways :P
I just wanted to check if there is any easier way.
Cuz it could have been like that, for example u put into mapping some extra data that tells what parrent tables refer to this table objects, and if this object is deleted hibernate automaticaly nulls parrent table keys values up by calling one update (update parrent table set refer_key=null where refer_key=deleted_object_key). But if there is no smth like that, i am fine with that and i know that there is no easier way :P
I will do it manualy :P

max · **Posted:** Fri Jul 28, 2006 1:13 pm

no blame placed - just trying to explain it by letting you think about what you are actually asking for ;)