Question

I have a MySQL table with foreign key constraints, eg.

CREATE TABLE `yiingles_version` (
  `id` int(11) unsigned NOT NULL AUTO_INCREMENT,
  `package_id` int(11) NOT NULL,
  `version` varchar(64) NOT NULL DEFAULT '',
  `distUrl` varchar(255) DEFAULT NULL,
  PRIMARY KEY (`id`),
  KEY `package_id` (`package_id`),

  CONSTRAINT `yiingles_version_ibfk_1` 
    FOREIGN KEY (`package_id`) REFERENCES `yiingles_package` (`id`) 
    ON DELETE CASCADE ON UPDATE CASCADE

) ENGINE=InnoDB DEFAULT CHARSET=utf8;

How can I get programmatically the values for ON DELETE and ON UPDATE, in this case CASCADE?

I’ve seen this question and also took a look at MySQL’s information_schema database, but did not find a way to get the values mentioned above.

Answer 1

Have a look at the information_schema.referential_constraints table. Specifically, the UPDATE_RULE and DELETE_RULE columns.