get_or_create fails on related queryset

[Phoenixfire159@…]

The following will fail with a cryptic error message,

class Counter(models.Model):
  name = CharField(max_length = 255)

class Point(models.Model):
  counter = ForeignKey(Counter)

counter = Counter.objects.get(name = 'some name')
points  = counter.points.all()
points.get_or_create(**some_parameters)

For some reason, get_or_create ends up executing a SQL INSERT statement

  INSERT INTO 'point_table' ('counter_id') VALUES (None)

Well, that's not the exact output, which I unfortunately can't really copy and paste here, but the point is that get_or_create ends up inserting a Point with a None value for counter_id.

The quick fix right now is,

  counter = Counter.objects.get(name = 'some name')
  points  = counter.points.all()

  some_parameters.update({ 'defaults': { 'counter': counter } })
  points.get_or_create(**some_parameters)

[Michael Radziej]

Does it really insert None for counter_id (resulting in an SQL syntax error), or rather NULL (resulting still in an error due to the "not null" constraint)? If it's the first case, please reopen the ticket.

In the latter case, this is expected behaviour which is described in detail in the documentation about get_or_create. It does not make a sense to use a restricted query set like this.