Renaming foreign-key columns in MySQL

Question

We're trying to rename a column in MySQL (5.1.31, InnoDB) that is a foreign key to another table.

At first, we tried to use Django-South, but came up against a known issue:

http://south.aeracode.org/ticket/243

OperationalError: (1025, "Error on rename of './xxx/#sql-bf_4d' to './xxx/cave_event' (errno: 150)")

AND

Error on rename of './xxx/#sql-bf_4b' to './xxx/cave_event' (errno: 150)

This error 150 definitely pertains to foreign key constraints. See e.g.

http://stackoverflow.com/questions/160233/what-does-mysql-error-1025-hy000-error-on-rename-of-foo-errorno-150-mea

http://www.xaprb.com/blog/2006/08/22/mysqls-error-1025-explained/

So, now we're trying to do the renaming in raw SQL. It looks like we're going to have to drop the foreign key first, then do the rename, and then add the foreign key back again. Does that sound right? Is there a better way, since this seems pretty confusing and cumbersome?

Any help would be much appreciated!

Answer 1

AFAIK, dropping the constraint, then rename, then add the constraint back is the only way. Backup first!