Category dependable content - in a twisted way

Frozen_Kiwi

I have a site with a two column layout where the left column content depends on the category. However I want it to be subcategory dependable - in a twisted way: the left column should be the same for every subcategory within a category except some specific subcategories (e.g. Plums) that should get their own content:

table subcats

subcat_id | subcat

1 | apples
2 | plums
3 | peaches

table left_column_content

text_id | cat_id | subcat_id | column_text

1 | 8 | 0 | asdfasdfk
2 | 8 | 0 | dfgdfghjk
4 | 8 | 2 | plumplum
3 | 8 | 2 | plumplum

I believe the query should be like this:

SELECT column_text
FROM left_column_content WHERE
CASE WHEN subcat_id = '$subcat_id'
THEN cat_id = '$cat_id' AND subcat_id = '$subcat_id'
ELSE cat_id = '$cat_id' AND subcat_id = '0'
END

Don't tell me, I know - the line (WHEN subcat_id = '$subcat_id') is all wrong and doesn't serve my purpose but it's just a placeholder as I just can't wrap my brains around this seemingly simple problem. If anyone could help, it would be greatly appreciated.

stiduck

I've never used a CASE in SQL, but you can look here and see if you can figure something out that helps you on the way... It's by the ANSI SQL-92 standard.

http://www.craigsmullins.com/ssu_0899.htm

stiduck

Frozen_Kiwi

Actually, I have no problem with the CASE expression itself but thanks anyway - your link is quite useful. 🙂

Frozen_Kiwi

I think I rephrase my question. The problem can be solved with two queries:

SELECT column_text
FROM left_column_content
WHERE cat_id = '$cat_id' 
AND subcat_id = '$subcat_id'

If the above query returns 0 rows, then another query is executed:

SELECT column_text
FROM left_column_content 
WHERE cat_id = '$cat_id' 
AND subcat_id = '0'

Is it possible to combine the queries? MySQL version is 4.0 so subqueries and other fancy stuff ain't available... 🙁