Horton

Re: [SQL] Using the IN predicate in an UPDATE...

Herouth Maoz <herouth@oumail.openu.ac.il>

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From: Herouth Maoz <herouth@oumail.openu.ac.il>
To: Thomas Good <tomg@admin.nrnet.org>, Leslie Mikesell <les@Mcs.Net>
Cc: pgsql-sql@postgreSQL.org
Date: 1998-10-18T09:24:53Z
Lists: pgsql-sql 
At 14:37 +0200 on 15/10/98, Thomas Good wrote:


> > Am I missing something here or is this the same as:
> > UPDATE table1 SET id = 2 WHERE id = 1;
> > ??
> >  Les Mikesell
> >    les@mcs.com
>
> 3) Les,  What are ya, some kinda smarta**?  Yeah, somebody was missing
> something, but it weren't you...  ;-)

Hmmm. Are you sure? The original query you presented had different
semantics. It meant "If the recnum has any occurence with id=1, change all
its occurences (even those with id=17) to id=2".

That was the reason why I suggested an "exists" query instead. The above is
only equivalent when each recnum has only one id.

Herouth

--
Herouth Maoz, Internet developer.
Open University of Israel - Telem project
http://telem.openu.ac.il/~herutma