db-derby-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Rick Genter" <rgen...@silverlink.com>
Subject RE: how to cascade on update? Not possible?
Date Tue, 16 Mar 2010 14:20:31 GMT
> From: Gabriele Kahlout [mailto:gabriele@mysimpatico.com]
> Sent: Tuesday, March 16, 2010 12:26 AM
> To: Derby Discussion
> Subject: Re: how to cascade on update? Not possible?
> 
> Okay, and how do you recommend I work around it?
> I should retrieve the effected tuples (the referencing) and store
> their values (onto the stack/heap) and then delete the records (since
> the referencing fields are primary keys), and then finally updated the
> referred to tuples, and then re-insert the data into the referencing
> table, with the appropriate modification.
> Unfortunately violation checking is done after each statement, and may
> not be deffered.

When I've had to do something like this in the past, I do it in three steps:

1) Insert the new value to be referenced in the referenced table.
2) Update the referencing records in the referencing table(s) to use the new value.
3) Delete the old value that was referenced from the referenced table.

I do this in a single transaction so that logical data integrity is maintained.

--
Rick Genter
Principal Software Engineer
Silverlink Communications

Mime
View raw message