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From Øystein Grøvlen <Oystein.Grov...@Sun.COM>
Subject Re: any feedback on this?
Date Tue, 24 Jun 2008 09:32:54 GMT
Alan Burlison wrote:

> I've hit another snag though - I want the index to be unique and I was 
> going to keep the case-converted column up-to-date using 'after' 
> triggers.  However you can't use after triggers to populate a column 
> which has a unique index.  If you use a multi-row insert, the triggers 
> don't fire until after *all* the rows have been inserted, which results 
> in multiple nulls in the case-converted columns, which in turn cause an 
> error because an unique index can't contain multiple nulls.

Derby 10.4 allows multiple nulls for unique columns.

> Bah.  Looks like I'm going to have to switch to MySQL after all. :-(

Øystein Grøvlen, Senior Staff Engineer
Sun Microsystems, Database Group
Trondheim, Norway

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