Hi,
I have an inheritance hierarchy, one entity in the hierarchy contains a CLOB field. I am using table per concrete class..

The SQL generated for this is of the form

SELECT Person.A, PersonB, Person.CLOBFIELD FROM {
SELECT Person.A, Person.B, null as CLOBFIELD from PERSON TPERSON
null as
UNION
SELECT Person.A, Person.B, Person.CLOBFIELD from PERSON TEMPLOYEE}

In SQLServer, this gives the exception:
com.microsoft.sqlserver.jdbc.SQLServerException: The text data type cannot be selected as DISTINCT because it is not comparable.

The UNION keyword cannot be used for queries including a CLOB.
Does anybody have a work around for this?
Note I am forced to use table per class as I have to integrate with an existing database,
Cheers

And you need to have an association to this superclass?
If not, you can simply map the superclass as @MappedSuperclass

I need associations to both classes. Does this mean hibernate cannot handle the CLOB? It could if the UNION could be change to UNION ALL.

OK I had a chat with Steve
You can change or subclass the SQLServer dialect to return true on supportsUnionAll()
http://opensource.atlassian.com/projects/hibernate/browse/HHH-2478

Hi,
Thanks for that.
I got it to work by extending SQLServer.
I was just wondering is there anyway I change the behaviour of SQLServer without extending it i.e. can I get a handle to it at runtime and just set this union all behaviour.
Kind Regards

nope, but we will change the default SQLDialect in the near future