Re: IN vs EXIIST

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От
Darren Ferguson
Тема
Re: IN vs EXIIST
Дата
Msg-id
Pine.LNX.4.44.0209191352010.8082-100000@thread.crystalballinc.com
Ответ на
Re: IN vs EXIIST (Jean-Luc Lachance)
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Re: IN vs EXIIST Jean-Luc Lachance <jllachan@nsd.ca>
I realized after he sent his notice this morning.

On Thu, 19 Sep 2002, Jean-Luc Lachance wrote:

> This is not what he wants.
> 
> He wants all keys that have only true for x.
> 
>  
> > Why areyou using the sub select. If you just want all the key1 where x is
> > true then the following will work
> > 
> > SELECT DISTINCT(key1) FROM a WHERE x = TRUE;
> > 
> > If you want all rows and don't care about duplicates then remove the
> > distinct.
> > 
> > Hope this helps
> > 
> > >
> > > I've seen many posts saying that using IN is not optimal and replacing
> > > it with EXISTS is much better. I've read the only docs but I can't
> > > understand the difference between the two or how to convert.
> > >
> > > Can someone point me to some other docs or explain to me how to convert?
> > > Or is my table schema wrong?
> > >
> > > Thanks!
> > >
> > > Jc
> > >
> 

-- 
Darren Ferguson

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