Question

I have a custom table created which has a foreign constraint on the core_website table. However, the on delete cascade isn’t working.

I did a search and found this relevant thread, which notes that the data types between the two columns have to be the same. Both data types are smallint(5).

I did notice one minor discrepancy in the column definition, which is that in core_website, Allow Null is not set, and Default is not set to zero, whereas in the account table, Allow Null is set and Default is zero. I didn’t think changing these would have any effect, but I went ahead and changed them on the account table to match, but that didn’t help.

CREATE TABLE `account` (
  `account_id` smallint(11) unsigned NOT NULL AUTO_INCREMENT,
  `website_id` smallint(5) unsigned DEFAULT '0',
  `code` varchar(64) NOT NULL DEFAULT '',
  PRIMARY KEY (`account_id`),
  UNIQUE KEY `code` (`code`),
  KEY `FK_WEBSITE_ID` (`website_id`),
  CONSTRAINT `FK_WEBSITE_ID` FOREIGN KEY (`website_id`) REFERENCES `core_website` (`website_id`) ON DELETE CASCADE ON UPDATE CASCADE
) ENGINE=InnoDB AUTO_INCREMENT=44 DEFAULT CHARSET=utf8

Answer 1

You need add foreign key to core_website table and point it to website_id field in account table. In other words, foreign key should be added to the dependent table and pointed to main table, in this case when you delete row from main table – row from dependent table will be deleted because of FK. In your case you did it “upside down”.