'NoneType' object has no attribute 'year' in admin change list when using date_hierarchy with a date field with null values

[Eric Walstad <eric@…>]

In changeset r7511

AttributeError
'NoneType' object has no attribute 'year'

Exception Type:  	AttributeError
Exception Value: 	'NoneType' object has no attribute 'year'
Exception Location: 	/usr/lib/python2.5/site-packages/django/contrib/admin/templatetags/admin_list.py in date_hierarchy, line 271

In the following, years is getting set to [None]. That seems to happen when there are null values in the date field, as best I can tell:

            years = cl.query_set.dates(field_name, 'year')
            return {
                'show': True,
                'choices': [{
                    'link': link({year_field: year.year}),
                    'title': year.year
                } for year in years]
            }

Local vars:

_[3] 	[]
cl 	<django.contrib.admin.views.main.ChangeList object at 0x89c628c>
day_field 	'date_paid__day'
day_lookup 	None
field_generic 	'date_paid__'
field_name 	'date_paid'
link 	<function <lambda> at 0x8b5af44>
month_day_format 	u'F j'
month_field 	'date_paid__month'
month_lookup 	None
year 	None
year_field 	'date_paid__year'
year_lookup 	None
year_month_format 	u'F Y'
years 	[None]

My temporary work around is to not use date_hierarchy in the admin ui.

[Evren Esat Özkan <sleytr@…>]

Confirmed, same here with r7512. Error disappearing after deleting the records which has null dates.

[oyvind]

duplicate of #7147

[daniellindsley]

Sorry, but this was not a duplicate of #7147. It is still a bug as of Django 1.2.X.

Fixing it to omit null dates is easy but creating a test for it is proving difficult. I'll try to upload a patch shortly.

[daniellindsley]

Django 1.2.X version of the patch

[daniellindsley]

Django 1.3 version of the patch

[daniellindsley]

I uploaded both a 1.2 & 1.3 version of the patch. However, the 1.3 is tests-only, as the same bug doesn't seem to be present in 1.3.

[Russell Keith-Magee]

Works for me; Provided test cases pass for me on trunk and 1.2.X.

[daniellindsley]

Sorry for reopening. After updating & addressing a data problem, worksforme. Wish I could set the status to "embarassingwasteofcoredevtime".

[Jacob]

Milestone 1.3 deleted

[anonymous]

is ind 1.4

[Aymeric Augustin]

Please don't reopen tickets anonymously without providing any details. If the problem still exists in 1.4, I recommend to file a new ticket with enough information for someone else to reproduce it. Thanks!

See the ​guidelines on reporting bugs for advice on what a good bug report looks like.

[Simon Litchfield]

If your database has nulls, make sure your model field knows about it. Just set null=True (or remove the nulls from the db).

[dfraser@…]

I had this problem and the cause turned out to be a date of 0000-00-00 and thus an exception at

/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/django/contrib/admin/templatetags/admin_list.py in date_hierarchy, line 350

occurred because of the None value at the head of the list of possible years. The relevant column in the table was defined as NOT NULL, so this is a MySQL related issue due to its defaults and the complexity resulting from them. Forcing a crash would be good because it makes one clean up the data, but a date of 0000-00-00 might be valid in some sense, so perhaps the code in admin_list.py should change?

I decided having a value of "unknown" was more appropriate given how the field was used, so I decided not to use the date_hierarchy feature.