Dynamically removing records when certain columns = 0; data cleansing

I have a simple card table:

CREATE TABLE `users_individual_cards` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `user_id` char(36) NOT NULL,
  `individual_card_id` int(11) NOT NULL,
  `own` int(10) unsigned NOT NULL,
  `want` int(10) unsigned NOT NULL,
  `trade` int(10) unsigned NOT NULL,
  PRIMARY KEY (`id`),
  UNIQUE KEY `user_id` (`user_id`,`individual_card_id`),
  KEY `user_id_2` (`user_id`),
  KEY `individual_card_id` (`individual_card_id`)
) ENGINE=MyISAM  DEFAULT CHARSET=latin1 AUTO_INCREMENT=1;

I have ajax to add and remove the records based on OWN, WANT, and TRADE. However, if the user removes all of the OWN, WANT, and TRADE cards, they go to zero but it will leave the record in the database. I would prefer to have the record removed. Is checking afte开发者_如何学JAVAr each "update" to see if all the columns = 0 the only way to do this? Or can I set a conditional trigger with something like:

//psuedo sql
AFTER update IF (OWN = 0, WANT = 0, TRADE = 0) DELETE

What is the best way to do this? Can you help with the syntax?

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Why not just fire two queries from PHP (or other front end)?

update `users_individual_cards` ...
delete `users_individual_cards` where ... (same condition) and own + want + trade = 0

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The trigger will be:

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CREATE TRIGGER users_individual_cards_trigger
    AFTER UPDATE ON users_individual_cards
    FOR EACH ROW
    BEGIN
    DELETE FROM users_individual_cards
    WHERE 'OWN' = 0 AND 'WANT' = 0 AND 'TRADE' = 0;
    END$$

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The solutions throw the delete query will be better because not all versions of mysql support it.