LookUp looks something like this:
Code: Select all
ID | SourceID | Type | DateAdded
------------------------------------
1 | 12 | A | 2009-04-28
2 | 4 | A | 2009-05-05
3 | 27 | B | 2009-05-05
4 | 12 | B | 2009-05-06
5 | 45 | A | 2009-05-08Code: Select all
SELECT *
FROM `LookUp`
JOIN `TableA`
ON IF(`LookUp`.`Type`='A', `SourceID`, NULL) = `TableA`.`ID`
JOIN `TableB`
ON IF(`LookUp`.`Type`='B', `SourceID`, NULL) = `TableB`.`ID`
ORDER BY `DATE` DESC
LIMIT 20