ON DELETE CASCADE not working in MySQL

Question

I am using the following SQL to create a table named app_info:

CREATE TABLE IF NOT EXISTS `app_info` (
`_id` int(11) NOT NULL AUTO_INCREMENT,
`         


        

Answer 1

The MyISAM storage engine doesn't support foreign key constraints. The constraint is parsed but silently ignored.

To fix your problem use the InnoDB engine instead (for both tables).

CREATE TABLE ( ... ) ENGINE = InnoDB ... ;

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Instead of dropping your tables and recreating them you can also change the storage engine:

ALTER TABLE myDB.app_info ENGINE = InnoDB;
ALTER TABLE myDB.tab_info ENGINE = InnoDB;

After changing the engine you will need to add the foreign key constraint again.