Re: MySQL Query Help

On Sat, 20 Nov 2010 13:54:29 -0700 "Ben Miller" <biprellim@gmail.com> wrote: > Hi, > > I'm building a website for a client in which I need to compare their > products, side-by-side, but only include criteria for which all selected > products have a value for that criteria. > > In my database (MySQL), I have a tables named "products","criteria" and > "criteria_values" > > If I have something like > > $selected_product = array("1"=>"Product > 1","2"=>"Product 2"...) // All > products selected for comparison by the user > > I need to get only rows from "criteria" where there is a row in > "criteria_values" matching "criteria.criteria_id" for each > $selected_product > - in other words, if any of the $selected_product does not have a row in > "criteria_values" that matches "criteria.criteria_id", that criteria would > not be returned. I hope that makes sense. It would be a lot easier to think about this if you could provide the table structure or create table statements. If I understood correctly, you have products which reference a criteria ID which has no matching value. If this is the problem you have a to first take care of the integrity of your data, as this should never happen. -- Simcha Younger <simcha@syounger.com>