Error with South when migrating changes to model

Question

I have added a foreign key to a user to a model, but when I try to migrate the database using South, I get the following error:

_mysql_exceptions.OperationalError: (1067, "Invalid default value for 'user_id'")

South tells me that I may be able to recover from the error by running an SQL command:

! You *might* be able to recover with:   = 
    ALTER TABLE `main_deal` DROP COLUMN `user_id` CASCADE; []

I tried to run the SQL command, but I get the following error:

#1091 - Can't DROP 'user_id'; check that column/key exists

Do I need to add 'user_id' to my model and set the default value to 1?

Edit: Here is the code that I added to my model to cause this to occur:

user = models.ForeignKey(User)

Then I migrated the model using South.

Please post the code for the model that you have modified. – Andrew Wilkinson Apr 04 '11 at 08:58 — Andrew Wilkinson, Apr 04 '11 at 08:58
I added the code that I modified in the model. – Kelp Apr 04 '11 at 17:00 — Kelp, Apr 04 '11 at 17:00

score 1 · Accepted Answer · answered Apr 05 '11 at 07:45

When you ran the schemamigration command, you should've been asked some questions about default values. If you gave the wrong answer it may have caused the problem you describe.

If you could open up the actual migration file and grab the forward method near the top, and post it here, I should be able to figure out what went wrong.

score 0 · Answer 2 · answered Apr 05 '11 at 07:55

I guess you have a problem because you specified not nullable user field without providing default value. You need to either provide default value eg. user = models.ForeignKey(User, default=foo) or allow nulls for user field user = models.ForeignKey(User, null=True)

Btw, I think that latest version of south asks for default values when migration is being created. Which version do you use?

Error with South when migrating changes to model

2 Answers2