php mysql updating in multiple tables

I have 3 tables:

• Products containing IDProduct, IDCategory, Name
• Suppliers containing IDSupplier, SupplierName, Phone
• ProductSup开发者_开发知识库plier containing IDProduct, IDSupplier, Price, Quantity

I want to update (edit) the following: IDCategory, Name(product), IDSupplier, Price, Quantity, but i'm not doing the UPDATE query right:

$query="UPDATE products P, 
               category C, 
               suppliers S, 
               productsupplier PS 
           SET P.IDCategory = '$idcategory', 
               P.Name = '$Name', 
               S.IDSupplier = '$idsupplier',  
               PS.Price = '$Price', 
               PS.Quantity = '$Quantity'
         WHERE ((IDProduct = '$idproduct') 
           AND (P.IDProdus = PF.IDProdus) 
           AND (PS.IDSupplier = S.IDSupplier ) 
           AND (P.IDCategory = C.IDCategory))");  

How do i do this right? Thank you!

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http://forums.mysql.com/read.php?20,85813,85813#msg-85813 this thread should give you all the answers you need. In essence you should be using a join.