From: Sasha Pachev
Date: March 31 1999 11:50pm
Subject: Re: How to UPDATE from field in other table
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Eric Berg wrote:
> 
> Christian,
> 
> Replace will kill the rest of the row, only assigning values where you
> specify (or to *).  Not what I want here.
> 
> I'm having no luck with the UPDATE one table from another approach, either.
> I think I'm going to create a file of update statements based on the source
> table.  Actually, I've done it already with a Perl script, but I wanted to do
> it within the SQL server.  Ah, well.
> 
> The one problem that I have is that I'd like to see the changes even for rows
> where the replacement/update value is the same as the current value.
> 
> -Eric.
> 
> Christian Mack: [Wednesday 31-March]:
> 
> > Eric Berg wrote:
> > >
> > > I'm trying to update a field in tableA to a value in a field in tableB based
> > > on a common key.  I get "ERROR 1109: Unknown table 'tableB' in field list"
> > > errors each time.
> > >
> > > update tableA
> > > set somefield=tableB.otherfield
> > > where tableA.keyfield=tableB.keyfield;
> > >
> > > How do I work around this?
> > >
> > > -Eric.
> >
> > Hi Eric
> >
> > The above is illegal SQL, because UPDATE uses only one table.
> >
> > Try the REPLACE ... SELECT ... syntax.
> >
> > Tschau
> > Christian
> >

You can write some very simple code in Perl or C that
will do any imaginable kind of update/clean-up. 


-- 
Sasha Pachev
http://www.sashanet.com/ (home)
http://www.direct1.com/ (work)