MySQL Error while dropping tables: Cannot delete or update a parent row: a foreign key constraint fails

18 Oct 2011 | by Marcin Pajdzik

If you need to drop several tables, for example because you need to then restore them, you may arrive at the following error:

ERROR 1217 (23000): Cannot delete or update a parent row: a foreign key constraint fails

That happens if there are tables with foreign keys references to the table you are trying to drop.

All you need to do is:

SET FOREIGN_KEY_CHECKS=0

Drop your tables

SET FOREIGN_KEY_CHECKS=1

IT Consultant and Contractor - London