IntegrityError using Django's loaddata when switching to Postgres

Question

I am getting the following error:

IntegrityError: duplicate key value violates unique constraint "users_userprofile_pkey"

I am migrating from MySQL to Postgres, so I am dumping the data from the MySQL database using:

python2.7 manage.py dumpdata --indent=4 --natural > dump.json

I get the error when I attempt to load the dump.json into the Postgresql database:

 python manage.py loaddata dump.json

I have the following signals in my users/model:

post_save.connect(create_user_profile, sender=User, dispatch_uid="user_create_profile")
post_save.connect(create_api_key, sender=User, dispatch_uid="user_create_api_key")

egidra · Accepted Answer · 2012-08-12 22:09:14Z

5

I had to comment out the post_save signals and then do the loaddata.

answered Aug 12, 2012 at 22:09

egidra

9,13721 gold badges68 silver badges92 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Hassek · Accepted Answer · 2012-08-09 05:06:49Z

0

the problem may be because of the --natural keyword, if you read the docs about dumpdata natural keys here you will see it has some problems that apply to your database migration.

Also here they talk about a solution to this problem which seems to be pretty interesting (and tedious).

You can always try to add first the models that doesn't depend on each other so you can be sure they exists before trying to create another one. i.e:

if you have this models:

class Person(models.Model):
    first_name = models.CharField(max_length=100)
    last_name = models.CharField(max_length=100)

    birthdate = models.DateField()

    class Meta:
        unique_together = (('first_name', 'last_name'),)

class Book(models.Model):
    name = models.CharField(max_length=100)
    author = models.ForeignKey(Person)

Then migrate the Person class first and then the book class.

Also if you can post the error it would be very helpful (since I could be more specific) but I am pretty certain the problem is a primary key issue

edited Aug 9, 2012 at 5:06

answered Aug 9, 2012 at 4:53

Hassek

9,0256 gold badges51 silver badges59 bronze badges

2 Comments

egidra Over a year ago

I have a UserProfile that relies on a User model. How do I only dump the User data (that's built in with Django). Also, what should the order be when two models depend on each other?

Hassek Over a year ago

for the user you can ´./manage.py dumpdata auth´ after that just dump your UserProfile. for models that depend on each other you should use the tedious approach I mentioned. Migrating a database is no easy task. here is another question that may help you out stackoverflow.com/questions/4964615/…

Collectives™ on Stack Overflow

IntegrityError using Django's loaddata when switching to Postgres

2 Answers 2

Comments

2 Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

2 Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related