I'm using fixtures with django.test.TestCase. If my test creates a model object and the fixture data already contains an object of the same type with pk=1, the new object will fail to save because of a pk clash. If my fixture data has pk=2, my created object is saved fine (with pk=1), but a subsequent object will fail with a pk clash (trying to use pk=2, already taken).
It's as if the sequence is not taking account of the primary key values that were explicitly set when the fixture was loaded. If I use psql to insert rows with pk specified, then insert rows without pk specified, the sequence handles it fine. I tested with Postgresql (8.1) using both the postgresql and postgresql_psycopg2 database engines.
Here's some example code to reproduce the problem (also app attached).
demo/models.py
from django.db import models
class Example(models.Model):
name = models.CharField(maxlength=100)
demo/fixtures/example.json
[
{
"pk": 1,
"model": "demo.example",
"fields":
{
"name": "example 1"
}
}
]
demo/tests.py
from django.test import TestCase
from demo.models import Example
class ExampleTestCase(TestCase):
fixtures = ['example']
def test_example(self):
new_example = Example.objects.create(name='new example')
./manage.py test demo
Error message:
======================================================================
ERROR: test_example (project.demo.tests.ExampleTestCase)
----------------------------------------------------------------------
Traceback (most recent call last):
File "/home/user/dev/project/web/project/../project/demo/tests.py", line 10, in test_example
new_example = Example.objects.create(name='new example')
File "/usr/lib/python2.4/site-packages/django/db/models/manager.py", line 79, in create
return self.get_query_set().create(**kwargs)
File "/usr/lib/python2.4/site-packages/django/db/models/query.py", line 262, in create
obj.save()
File "/usr/lib/python2.4/site-packages/django/db/models/base.py", line 238, in save
','.join(placeholders)), db_values)
IntegrityError: duplicate key violates unique constraint "demo_example_pkey"
