How can I temporarily disable a foreign key constraint in MySQL?

mysql sql django django-models
jul picture jul · Mar 19, 2013 · Viewed 687.2k times · Source

Is it possible to temporarily disable constraints in MySQL?

I have two Django models, each with a foreign key to the other one. Deleting instances of a model returns an error because of the foreign key constraint:

cursor.execute("DELETE FROM myapp_item WHERE n = %s", n)
transaction.commit_unless_managed()  #a foreign key constraint fails here

cursor.execute("DELETE FROM myapp_style WHERE n = %s", n)
transaction.commit_unless_managed()

Is it possible to temporarily disable constraints and delete anyway?

Answer

Andrew Campbell picture Andrew Campbell · Mar 19, 2013

Try DISABLE KEYS or

SET FOREIGN_KEY_CHECKS=0;

Make sure to

SET FOREIGN_KEY_CHECKS=1;

after.

Related questions

How can I allow django admin to set a field to NULL?

I've set my Model field to null=True, which allows NULL in MySQL, but I can't seem to assign NULL to the field through Django Admin. I've tried also setting blank=True, but that just sets the field to an …

Read More
How to compare version string ("x.y.z") in MySQL?

I have firmware version strings into my table (like "4.2.2" or "4.2.16") How can I compare, select or sort them ? I cannot use standard strings comparison : "4.2.2" is a seen by SQL greater than "4.2.16" As version strings, I would like 4.2.16 to be greater …

Read More
How do I import an SQL file using the command line in MySQL?

I have a .sql file with an export from phpMyAdmin. I want to import it into a different server using the command line. I have a Windows Server 2008 R2 installation. I placed the .sql file on the C drive, and …

Read More