id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
22571	DateTimeField(auto_now_add=True) Breaks	nu.everest@…	nobody	"Example:
# Given this simple model
class Foo(models.Model):
    name = models.CharField(max_length=100)
    date_added = models.DateTimeField(auto_now_add=True)

# This will always be true, even if an instance
# with this name and today's date already exists

bar, created = Foo.objects.get_or_create(
    name = 'Alex', 
    date_added = some_datetime_obj
)

print created
# >> True


# The problem is, auto_now_add does some stuff that 
# makes it uneditable, and messes up my expectations
# when using it with get_or_create

# Here's the solution
class Foo(models.Model):
    name = models.CharField(max_length=100)
    date_added = models.DateTimeField(default=datetime.today())

bar, created = Foo.objects.get_or_create(
    name = 'Alex', 
    date_added = some_datetime_obj
)

print created
# >> False

Error:
django.db.utils.IntegrityError: duplicate key value violates unique constraint


These two links document the issue:
http://alexkehayias.tumblr.com/post/33889961953/django-gotcha-duplicate-models-when-using

http://stackoverflow.com/questions/9297422/get-or-create-failure-with-django-and-postgres-duplicate-key-value-violates-uni"	Uncategorized	new	Uncategorized	1.4	Normal		integrityerror auto_now_add get_or_create duplicatekey		Unreviewed	0	0	0	0	0	0