Re: Query to return modified results at runtime?

<pre class="SCREEN">Hi,


You can use the construct <b>Case When</b> but You have to have
Your information structured (even if only in Your mind) 
in order to achive the results You want.

So, suposse You have for the color Blue the letter A,
for the color Red the letter D, for the color Green the 
letter B and finally for the color Orange the letter C.

For the following data:

create table dcosta.colors
(id     numeric(3),Color  varchar(12));

insert into dcosta.colors values(1, 'Blue');
insert into dcosta.colors values(2, 'Red');
insert into dcosta.colors values(3, 'Green');
insert into dcosta.colors values(4, 'Orange');

You can use the following instruction:

<b>
</b>SELECT ID, Color,       CASE WHEN color = 'Blue'   THEN 'A'           WHEN color = 'Red'    THEN 'D'           WHEN
color= 'Green'  THEN 'B'           WHEN color = 'Orange' THEN 'C'           ELSE 'other'      END
 
FROM dcosta.colors;</pre><br /> Obviously You can ommit the column Color from the select clause.<br /><br /><br /> Hope
Ihelped<br /> Dias Costa<br /><br /><br /><br /><br /> George Handin wrote: <blockquote
cite="mid44884752.7030303@dafunks.com"type="cite">Richard Broersma Jr wrote: <br /><blockquote type="cite"><blockquote
type="cite">ID   Color <br /> ---   ------- <br /> 1     Blue <br /> 2     Red <br /> 3     Green <br /> 4     Orange
<br/><br /> How would I rewrite the query to return results where the colors are replaced by letters to give the
followingresults? <br /><br /> ID    Color <br /> ---   ------- <br /> 1     A <br /> 2     D <br /> 3     B <br />
4    C <br /></blockquote><br /><br /><a class="moz-txt-link-freetext"
href="http://www.postgresql.org/docs/8.1/interactive/functions-conditional.html">http://www.postgresql.org/docs/8.1/interactive/functions-conditional.html</a><br
/><br/> this is probably the easiest to implement but hard to mangage over time.  Another solution would <br /> be to
createcolor_code table that is referenced by your test table.  Then when you can create a <br /> query as: select a.ID,
b.codefrom test as a join color_code as b on a.color = b.color; <br /><br /> There are additional solutions to this
also.But these two are probably the easiest. <br /></blockquote><br /> Thanks! <br /><br />
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