Subject: Re: Problem with a lookup table!  Please help.
From: Oliver Elphick <olly@lfix.co.uk>
To: Chris Jewell <vs0u8055@liv.ac.uk>
Cc: pgsql-sql@postgresql.org
In-Reply-To: <000f01c29fc5$afc34960$2301a8c0@chrisdomain>
References: <000f01c29fc5$afc34960$2301a8c0@chrisdomain>
Content-Type: text/plain
Organization: LFIX Limited
Message-Id: <1039486074.20146.43.camel@linda.lfix.co.uk>
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Date: 10 Dec 2002 02:07:54 +0000
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On Mon, 2002-12-09 at 20:58, Chris Jewell wrote:
> ...
> However, I now want to have a new table which converts numbers into
> words.  The problem is this, if I join the main table with the
> "translation" lookup table, the column names for each of the four
> categories in the main default to the column name in the lookup table
> and hence are all the same.  What SQL expression should I use to
> translate the cryptic numbers into plain english whilst preserving the
> column headings in the main table?

You just need to name the columns:

  SELECT t.antibiotic,
         e1.plain_english AS "Activity against grampos",
         e2.plain_english AS "Activity against gramneg",
         e3.plain_english AS "Activity against aerobes",
         e4.plain_english AS "Activity against anaerobes"
    FROM tblantibiotics AS t,
         efficacy AS e1,
         efficacy AS e2,
         efficacy AS e3,
         efficacy AS e4
   WHERE t.activity_against_grampos = e1.efficacy_code AND
         t.activity_against_gramneg = e2.efficacy_code AND
         t.activity_against_aerobes = e3.efficacy_code AND
         t.activity_against_anaerobes = e4.efficacy_code;

Note that you must use double quotes to quote identifiers, not single
quotes as you did in your table creation definitions, which won't work
in PostgreSQL.

-- 
Oliver Elphick                                Oliver.Elphick@lfix.co.uk
Isle of Wight, UK                             http://www.lfix.co.uk/oliver
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