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Date: Wed, 3 Jul 2013 19:29:34 -0400
From: Bruce Momjian <bruce@momjian.us>
To: Dev Kumkar <devdas.kumkar@gmail.com>
Cc: Tom Lane <tgl@sss.pgh.pa.us>, Alvaro Herrera <alvherre@2ndquadrant.com>,
 Thomas Kellerer <spam_eater@gmx.net>, pgsql-sql@postgresql.org
Subject: Re: Unquoted column names fold to lower case
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On Thu, Jul  4, 2013 at 02:00:24AM +0530, Dev Kumkar wrote:
> On Thu, Jul 4, 2013 at 1:36 AM, Bruce Momjian <bruce@momjian.us> wrote:
> 
>     And let's not forget that column aliases can be used as indentifiers in
>     queries:
> 
>             test=> SELECT 1 AS x
>             test-> ORDER BY x;
>              x
>             ---
>              1
>             (1 row)
> 
>             test=> SELECT 1 AS "X"
>             ORDER BY x;
>             ERROR:  column "x" does not exist
>             LINE 2: ORDER BY x;
> 
>     Changing this would mean that the same identifier would have different
>     case-folding rules depending on where it appeared in the query.
> 
>  
> Sorry but I am not sure about your point here. Currently if the alias is quoted
> then same needs to be used in queries as identifies:
> SELECT 1 AS "X"
>         ORDER BY "X";

You would need to double-quote 'x' in the ORDER BY, but not in the
target list (because case would be preserved there)  --- that is
confusing.

-- 
  Bruce Momjian  <bruce@momjian.us>        http://momjian.us
  EnterpriseDB                             http://enterprisedb.com

  + It's impossible for everything to be true. +


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