How can I add ON DELETE constraint on the table?

Question

How can I add ON DELETE constraint on the table?

Answer 1

If the foreign key is already created, there is a trick that worked for me. You can modified the dump of your database and import it again with the modifications.

If you are using Mysql and Linux shell, it'd be like this:

First, export your database:

$ mysql -u  -p  > database.sql

Then, open the database.sql file and look for the table you want to alter.

Add ON DELETE CASCADE at the end of the foreign key sentence and save it.

Second, import your database with the modifications:

$ mysql -u  -p  < database.sql

And you will have your ON DELETE CASCADE working.