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Re: SQL command speed

From: "Stephan Szabo" <sszabo(at)kick(dot)com>
To: "Ross J(dot) Reedstrom" <reedstrm(at)wallace(dot)ece(dot)rice(dot)edu>
Cc: <pgsql-sql(at)postgresql(dot)org>
Subject: Re: SQL command speed
Date: 2000-05-18 22:02:02
Message-ID: 024001bfc114$b25c18b0$0c64010a@kick.com (view raw or flat)
Thread:
Lists: pgsql-sql
I didn't see a function that would do what you wanted to do, but
I guess you could do the trimming in a plpgsql function though...
(Since I don't have a 7.0 system to test with, these were only tested
on an old 6.5.1 database)...

create function trimthe(text) returns text as '
begin
if (substr($1, 1, 4) = \'The \' then
 return substr($1, 5);
end if;
-- add other prefix checks here...
return $1;
end;
' language 'plpgsql';

and then select ordering by that...  

I guess a more general function could be:
create function ltrimstr(text, text) returns text as '
begin
 if position($2 in $1) = 1 then
  return substr($1, char_length($2)+1);
end if;
return $1;
end;
' language 'plpgsql';


----- Original Message ----- 
From: "Ross J. Reedstrom" <reedstrm(at)wallace(dot)ece(dot)rice(dot)edu>
To: <pgsql-sql(at)postgresql(dot)org>
Sent: Thursday, May 18, 2000 1:39 PM
Subject: Re: [SQL] SQL command speed


> Hey crew:
> I've got a relatively simple SQL problem. In a db backed web site
> we're building, I'd like to fill a dropdown box with the contents of a
> validation table, in this case research institutions. I want to sort them
> alphabetically, but using "library rules": i.e. skip inital articles,
> since we've a few 'The University of Foo" and "The Johns Hopkins
> University", for example.
> 
> I thought I had it with this SQL:
> 
> SELECT InstName from Institutions ORDER BY ltrim (InstName, 'The');
> 
> Looked good, until I found 'Texas A&M University' sorting below York.
> 
> Seems ltrim() removes inital charaters from the set of charaters, not
> inital strings, so I was sorting on 'xas A&M University'
> 
> Anyone have some magic solution for this?



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Next:From: Ross J. ReedstromDate: 2000-05-18 22:03:18
Subject: Library sort order (was Re: SQL command speed)
Previous:From: Tom LaneDate: 2000-05-18 21:47:56
Subject: Re: SQL command speed

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