I'm more of an hit and try guy and do good only with a data set available. Still I think making a little change might do the trick. SELECT DISTINCT p.productid, pd.name FROM menu_product as p INNER JOIN menu as m ON (m.menuid = p.menuid AND m.name = '<name obtained from user's click>') INNER JOIN product_description as pd ON (pd.productid = p.productid) LEFT JOIN menu as m2 ON (m2.parent_menuid = m.menuid) # User selected menu may itself be a child menu... WHERE p.productid IN (SELECT p2.productid from menu_product AS p2 WHERE p2.menuid = m2.menuid)
Hope that works. Regards, ________________________________ From: rich gray <r...@richgray.com> To: mysql@lists.mysql.com Sent: Monday, August 27, 2012 2:46 AM Subject: Having trouble with SQL query I have a MySQL database with a menu table and a product table linked to the menus *(each product can be linked to more than menu row)* and the menus are nested. The query is that when a user clicks on a menu entry then all products linked to that entry *(there may be none)* will get displayed as well as all products linked to child menus... below are describe tables for the 2 main tables in question (there is a 3rd table that holds product descriptions which I won't show as I don't think it is relevant) CREATE TABLE `menu` ( `menuid` int(11) unsigned NOT NULL AUTO_INCREMENT, `parent_menuid` int(11) unsigned NOT NULL, `name` varchar(255) NOT NULL, PRIMARY KEY (`menuid`) ) ENGINE=MyISAM AUTO_INCREMENT=225 DEFAULT CHARSET=utf8 CREATE TABLE `menu_product` ( `menuid` int(11) unsigned NOT NULL, `productid` int(11) unsigned NOT NULL, PRIMARY KEY (`menuid`,`productid`), KEY `prodidx` (`productid`) ) ENGINE=MyISAM DEFAULT CHARSET=utf8 Anyway for the sake of this question lets say there is only 2 levels of nesting so a parent menu can only have children so no grandkids+ this is the query I came up with:- SELECT DISTINCT p.productid, pd.name FROM menu_product as p INNER JOIN menu as m ON (m.menuid = p.menuid) INNER JOIN product_description as pd ON (pd.productid = p.productid) LEFT JOIN menu as m2 ON (m2.parent_menuid = m.menuid) # User selected menu may itself be a child menu... WHERE (m.name = '<name obtained from user's click>' OR p.productid IN (SELECT p2.productid from menu_product AS p2 WHERE p2.menuid = m2.menuid) Anyway the above query returns many many entries from menus that are totally unrelated... I have been staring too hard at this for too long - I am sure it will be a forehead slapper! I hope I have explained this sufficiently and I TYIA for any guidance Rich -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/mysql
