MySQL - How to DROP CONSTRAINT in MySQL?

In MySQL (before 8.0.19), there's no DROP CONSTRAINT, you have to use DROP FOREIGN KEY instead:

ALTER TABLE `table_name`
	DROP FOREIGN KEY `id_name_fk`;

You might have to drop the index too because simply removing foreign key doesn't remove the index.

ALTER TABLE `table_name` 
	DROP INDEX  `id_name_fk`;

An alternative to temporarily disable all the foreign keys:

SET FOREIGN_KEY_CHECKS=0;

When you need to turn it on:

SET FOREIGN_KEY_CHECKS=1;

Using TablePlus

In TablePlus, you can remove Foreign Key Constraint on a column from the Table Structure view:

• Open the table structure view (⌘ + ^ + ])
• Click on the foreign_key field and select to open the current foreign relationship
• From the popup, click on DELETE.
• Press ⌘ + S to commit changes to the server.

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