Preventing entire JOINed MYSQL query from failing when one field is missing within a WHERE clause

Posted by filip o on Stack Overflow See other posts from Stack Overflow or by filip o
Published on 2010-03-12T06:46:35Z Indexed on 2010/03/12 6:57 UTC
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mysql

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php

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joins

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variables

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fields

I am doing a couple of joins with a variable in the WHERE clause. I'm not sure if I am doing everything as efficiently as I could, or even using the best practices but my issue is that half my tables have data for when tableC.type=500, and the other half don't resulting in the entire query failing.

SELECT tableA.value1 , tableB.value2, tableC.value3 FROM tableA  
JOIN tableB ON  tableB.id=tableA.id
JOIN tableC ON  tableC.id=tableB.id
WHERE tableA.category=$var && tableC.type=500;

What I would like to happen is to still get tableA.value1 and tableB.value2 even if there is no field in tableC with a type=500.
any thoughts? i'm totally stumped as how to approach this...

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