getting and creating with get_or_create behave differently when using a foreign key

[KyleMac]

Using the following models:

class Product(models.Model):
    name = models.CharField()

class Stat(models.Model):
    product = models.ForeignKey(Product)
    value = models.PositiveIntegerField()

If you do the following and the row doesn't exist:

Stat.objects.get_or_create(product__id=1, defaults={'value': 0})

you will get an exception that product_id cannot be null (i.e. the create is failing).

However, if you do the following instead:

Stat.objects.get_or_create(product_id=1, defaults={'value': 0})

you get an exception that product_id cannot be resolved to a field (i.e. the get is failing).

The solution is to do something like:

Stat.objects.get_or_create(product=Product(id=1), defaults={'value': 0})

[Karen Tracey]

This is #5535.