Re: WHERE on an alias - Mailing list pgsql-sql

From Stephan Szabo
Subject Re: WHERE on an alias
Date
Msg-id Pine.BSF.4.21.0108241225480.23698-100000@megazone23.bigpanda.com
Whole thread Raw
In response to WHERE on an alias  (Joseph Shraibman <jks@selectacast.net>)
List pgsql-sql
On Fri, 24 Aug 2001, Joseph Shraibman wrote:

> playpen=# select a, sum(b) as dsum from taba where dsum > 5 group by(a);
> ERROR:  Attribute 'dsum' not found
> 
> Why can we GROUP BY on an alias but not do a WHERE on an alias?  I have a subselect that 
> explain shows is being run twice if I have to put it in the WHERE clause.

Somewhat unrelated question, are you sure you want where and not having?
IIRC, where is going to select rows before things like the group by
occur, and that doesn't seem to be what you'd want here, right?



pgsql-sql by date:

Previous
From: Joseph Shraibman
Date:
Subject: Re: WHERE on an alias
Next
From: Joseph Shraibman
Date:
Subject: Re: WHERE on an alias