LEFT JOIN problems

From: Date: Wed, 15 Nov 2000 08:33:03 +0000
Subject: LEFT JOIN problems
Groups: php.general 
Request: Send a blank email to php-general+get-25557@lists.php.net to get a copy of this message
If I have three tables, purely for demonstration t1 ID name 123 truck t2 ID img 123 1.jpg 123 2.jpg 123 3.jpg t3 ID cat 123 auto SELECT * FROM t1, t2, t3; ID name ID img ID cat 123 truck 123 1.jpg 123 auto 123 truck 123 2.jpg 123 auto 123 truck 123 3.jpg 123 auto 123 truck 123 4.jpg 123 auto now this is all fine, but as you know if any of the tables are empty then we have a problem, no results will be returned. SELECT * FROM t1, t2 left join t3 using (ID); I can use a left join, this will fix the case where there are no images. but what if the product has no image or categories? SELECT * FROM t1 left join t2 using (ID) left join t3 using (ID); This will work now. under a few cases. -All tables have info -t1 has data, t2 has data, and t3 doesn't but... mysql doesnt work like I want it to and places NULL in t3's variables if t2 has no data. it doesnt matter whats in t3, if t2 has nothing in it, then Im hooped. Chris Lee

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