[thelist] sql: LEFT JOIN and WHERE clause trouble
Ken Schaefer
ken at adOpenStatic.com
Tue Aug 12 20:05:43 CDT 2003
I think this'll do what I think you want (if that makes sense!):
SELECT
p.id
, p.name
, pmed.url
FROM
products AS p
LEFT JOIN
products_media AS pmed
ON
pmed.prodid = p.id
AND
pmed.type = 0
WHERE
p.product_isactive = 1
Cheers
Ken
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
From: "Chris W. Parker" <cparker at swatgear.com>
Subject: [thelist] sql: LEFT JOIN and WHERE clause trouble
<snip>
When I do a query for all products in the database I'm only given the
two products that have corresponding records in the products_media
table. What I want to have returned to me is ALL the products in the
database whether or not they have a record in the products_media table.
*BUT* if they do in fact have a record in the products_media table it
must have a type of 0 and nothing else.
Does that make sense?
How can I accomplish this? Do I need to resort to my code and not rely
on SQL to perform this? Using code would be much easier but it just
seems like it would be a lot more expensive (processor time wise) than
having the SQL engine do it.
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