Hi Daevid If you are using a foreign key you can set the reference as "cascade" and when a row is deleted from feed it will be deleted from feed_tag.
http://dev.mysql.com/doc/refman/5.0/en/innodb-foreign-key-constraints.html If you don't like it you can delete it easy with a query like this delete from feed_tag where id not in (select id from tag) Best, Isart On Wed, Aug 13, 2008 at 5:51 PM, Daevid Vincent <[EMAIL PROTECTED]> wrote: > I want to remove all records from 'feed_tag' where the feed_id foreign key > doesn't have any corresponding records in feed. > > For instance I may have a record in feed_tag that is like (23, 10, 4543, > '... (some date)'). > > Then lets say there is no record in feed that has a primary id key of 10. > > I want that record (or usually records because of the 1 feed to many > feed_tag relationship) to be removed. > > CREATE TABLE IF NOT EXISTS `feed` ( > `id` int(11) NOT NULL auto_increment, > `title` varchar(100) default NULL, > `url` varchar(255) default NULL, > `host` varchar(100) default NULL, > `type` varchar(100) default NULL, > `status` char(1) default NULL, > `total_stories` int(11) default '0', > `created_at` datetime default NULL, > `updated_at` datetime default NULL, > PRIMARY KEY (`id`) > ) ENGINE=InnoDB DEFAULT CHARSET=utf8 ; > > CREATE TABLE IF NOT EXISTS `feed_tag` ( > `id` int(11) NOT NULL auto_increment, > `feed_id` int(11) default NULL, > `tag_id` int(11) default NULL, > `created_at` datetime default NULL, > PRIMARY KEY (`id`), > KEY `feed_tag_FI_1` (`feed_id`), > KEY `feed_tag_FI_2` (`tag_id`) > ) ENGINE=InnoDB DEFAULT CHARSET=utf8 ; > > As you can see the foreign key 'feed_id' is the issue here (ignore the > tag_id key). > > > -- > MySQL General Mailing List > For list archives: http://lists.mysql.com/mysql > To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED] > > -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
