Message-ID: <435979B0.60107@ultimeth.com>
Date: Fri, 21 Oct 2005 16:28:48 -0700
From: "Dean Gibson (DB Administrator)" <postgresql4@ultimeth.com>
Organization: UltiMeth Systems
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To: pgsql-sql <pgsql-sql@postgresql.org>
Subject: Blank-padding (was: Oracle buys Innobase)
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On 2005-10-21 09:47, Tom Lane wrote:
> Alex Turner <armtuk@gmail.com> writes:
>   
>> It appears that casting to a char() causes spaces to be stripped (ignored) from the string:
>>     
> mls=# select length('123 '::char(8));
> length
> --------
> 3
> (1 row)
>
>   
>> I'm not sure about anyone else, but I would personaly consider that a bug?
>>     
>
> No, it's a feature, as per extensive discussion some time ago when we made it do that.  The general rule is that trailing spaces in a char(n) are semantically insignificant.
>
> 			regards, tom lane
>   

I remember that discussion, and I was for the change.  However, upon 
doing some testing after reading the above, I wonder if the 
blank-stripping isn't too aggressive.  I have a CHAR(6) field (say, 
named Z) that has "abc   " in it.  Suppose I want to append "x" to Z, 
with any leading spaces in Z PRESERVED.  The following do not work in 8.0.4:

select Z || 'x';

select Z::char(6) || 'x';

select Z::varchar(6) || 'x';

select (Z || '     ')::char(6) || 'x';

There are only two ways I've found:

select rpad( Z, 6) || 'x'; -- but "rpad" is apparently not a 
SQL-standard function.

select cast (Z || '      ' as varchar(6)) || 'x';  -- hokey but 
SQL-compliant

Is there something I'm missing???

-- Dean