Re: JOIN a UNION - Mailing list pgsql-general

From Pavel Stehule
Subject Re: JOIN a UNION
Date
Msg-id 162867790908061133o14097d2dv80f650da9c15a2f6@mail.gmail.com
Whole thread Raw
In response to Re: JOIN a UNION  ("david.schruth" <dschruth@gmail.com>)
Responses Re: JOIN a UNION
List pgsql-general
Hello

SELECT ... FROM
  (SELECT ... FROM A
   UNION ALL
   SELECT FROM B) s1
 JOIN C IN C.z = s1.z;

Regards
Pavel Stehule

2009/8/6 david.schruth <dschruth@gmail.com>:
> I just realized what I posted was perfectly valid SQL. The following
> is more what I had in mind:
>
> (SELECT x,y,z FROM A
> UNION
> SELECT x,y,z FROM B)
> AB JOIN C ON C.z = AB.z
>
> This version certainly does throw an error.
>
> Basically I'm wondering if there is a way to get Postgres to treat the
> result of a UNION as a table on which I could perform subsequent
> operations (like a JOIN).
>
> On Aug 6, 10:43 am, "david.schruth" <dschr...@gmail.com> wrote:
>> Simple question:
>>
>> Is there a way to do something like the following:
>>
>> SELECT x,y,z FROM A
>> UNION
>> SELECT x,y,z FROM B
>> JOIN C ON C.z = B.z
>>
>> Thanks,
>>
>> Dave
>
>
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