Re: IN vs EXIIST
От | Jean-Luc Lachance |
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Тема | Re: IN vs EXIIST |
Дата | |
Msg-id | 3D8A0FFA.B1FEF32A@nsd.ca обсуждение исходный текст |
Ответ на | Re: IN vs EXIIST (Darren Ferguson <darren@crystalballinc.com>) |
Ответы |
Re: IN vs EXIIST
|
Список | pgsql-general |
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 > >
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