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从MySQL表中获取外键约束

[英]Getting foreign key constraints from a MySQL table

I have a MySQL table with foreign key constraints, eg. 我有一个带有外键约束的MySQL表,例如。

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 ? 如何以编程方式获取ON DELETEON UPDATE的值,在本例中为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. 我已经看到了这个问题并且还看了一下MySQL的information_schema数据库,但没有找到获得上述值的方法。

Have a look at the information_schema.referential_constraints table. 看一下information_schema.referential_constraints表。 Specifically, the UPDATE_RULE and DELETE_RULE columns. 具体来说,是UPDATE_RULEDELETE_RULE列。

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