ERROR 1025 (HY000): Error on rename of... on MODIFY COLUMN

Question

I have a tb_denunciation with a denouncer_id int(10) unsigned column with a foreign key referencing the tb_user(user_id).

I need to add NOT NULL to the denouncer_id. I already checked that there are no null values in this column and (of course, there's a foreign key) all denouncer_id values match to some user_id on the tb_user.

I'm running this command:

ALTER TABLE tb_denunciation MODIFY denouncer_id int(10) unsigned not null;

And I get the error:

ERROR 1025 (HY000): Error on rename of './my_db_schema/#sql-1153_1b4133' to './my_db_schema/tb_denunciation' (errno: 150)

I've googled that this error is related do foreign keys, but all I could check is ok. Whats wrong?

Answer 1

I think you need to first remove the foreign key, and then do the column altering. Then you may add back the foreign key again after it's altered.