DML Upate for joined subclass

look_as1 · **Joined:** Mon Jan 23, 2006 10:04 am **Posts:** 9

Hi,

I have got problems using DML update in combination with joined subclass.
When I call statement like:

Code:

UPDATE joinedSubClass SET ATRIBUTE=10

I got following exception:

HibernateException( "cannot perform multi-table updates using dialect not supporting temp tables" ) from MultiTableUpdateExecutor .

I don't undestand why Hibernate need to create temporary tables? Why it does'not simply call on or more updates? (depends on which column do I update)?

Who is right? My idea about how joined sublcass should work or Hibernate implementation of DML?

Hibernate version: 3.1.1
Database: Firebird 1.5.3

max · **Posted:** Mon Jan 30, 2006 1:33 pm

because the structure is done across multiple tables it cannot be done in one single update and if you do it in mutliple updates the following update statements might now match correctly on the now changed columns...thus the need for storing the related ids in a temp table.

look_as1 · **Joined:** Mon Jan 23, 2006 10:04 am **Posts:** 9

I mean it's easy to check, whether one or more tables are changed.
At least for simple statements as mine was.
Can I commit this patch?

max · **Posted:** Mon Jan 30, 2006 2:27 pm

eh - yo did not mention any patch in the first posting...if you have code that improves hibernate then yes, feel free.