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
22512	Adding auto_now field to model causes migrate exception	James Addison	nobody	"I have a feeling this bug has already been filed, but I couldn't (easily) find it.

It looks like the makemigrations command is failing to import (or use) the datetime module properly. My steps:

* On an existing model, add a DateTimeField with `auto_now=True` set
* Run `makemigrations` command
* Run `migrate` command

Result is an exception, detailed below.

Calling makemigrations:

{{{
(project1)jaddison@jamess-air-2:~/projects/project1 (master)$ ./manage.py makemigrations
You are trying to add a non-nullable field 'updated' to contentlink without a default;
we can't do that (the database needs something to populate existing rows).
Please select a fix:
 1) Provide a one-off default now (will be set on all existing rows)
 2) Quit, and let me add a default in models.py
Select an option: 1       
Please enter the default value now, as valid Python
The datetime module is available, so you can do e.g. datetime.date.today()
>>> datetime.datetime.now()
Migrations for 'content':
  0003_contentlink_updated.py:
    - Add field updated to contentlink
}}}

Calling migrate:

{{{
(project1)jaddison@jamess-air-2:~/projects/project1 (master)$ ./manage.py migrate
Traceback (most recent call last):
  File ""./manage.py"", line 10, in <module>
    execute_from_command_line(sys.argv)
  File ""/Users/jaddison/.virtualenvs/project1/lib/python2.7/site-packages/django/core/management/__init__.py"", line 427, in execute_from_command_line
    utility.execute()
  File ""/Users/jaddison/.virtualenvs/project1/lib/python2.7/site-packages/django/core/management/__init__.py"", line 419, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File ""/Users/jaddison/.virtualenvs/project1/lib/python2.7/site-packages/django/core/management/base.py"", line 288, in run_from_argv
    self.execute(*args, **options.__dict__)
  File ""/Users/jaddison/.virtualenvs/project1/lib/python2.7/site-packages/django/core/management/base.py"", line 337, in execute
    output = self.handle(*args, **options)
  File ""/Users/jaddison/.virtualenvs/project1/lib/python2.7/site-packages/django/core/management/commands/migrate.py"", line 62, in handle
    executor = MigrationExecutor(connection, self.migration_progress_callback)
  File ""/Users/jaddison/.virtualenvs/project1/lib/python2.7/site-packages/django/db/migrations/executor.py"", line 14, in __init__
    self.loader = MigrationLoader(self.connection)
  File ""/Users/jaddison/.virtualenvs/project1/lib/python2.7/site-packages/django/db/migrations/loader.py"", line 48, in __init__
    self.build_graph()
  File ""/Users/jaddison/.virtualenvs/project1/lib/python2.7/site-packages/django/db/migrations/loader.py"", line 145, in build_graph
    self.load_disk()
  File ""/Users/jaddison/.virtualenvs/project1/lib/python2.7/site-packages/django/db/migrations/loader.py"", line 103, in load_disk
    migration_module = import_module(""%s.%s"" % (module_name, migration_name))
  File ""/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/importlib/__init__.py"", line 37, in import_module
    __import__(name)
  File ""/Users/jaddison/projects/project1/content/migrations/0003_contentlink_updated.py"", line 6, in <module>
    class Migration(migrations.Migration):
  File ""/Users/jaddison/projects/project1/content/migrations/0003_contentlink_updated.py"", line 16, in Migration
    field=models.DateTimeField(default=datetime(2014, 4, 25, 4, 32, 56, 89929), auto_now=True),
TypeError: 'module' object is not callable
}}}

The contents of the generated migration `0003_contentlink_updated.py`:

{{{
# encoding: utf8
from django.db import models, migrations
import datetime


class Migration(migrations.Migration):

    dependencies = [
        ('content', '0002_contentlink_body'),
    ]

    operations = [
        migrations.AddField(
            model_name='contentlink',
            name='updated',
            field=models.DateTimeField(default=datetime(2014, 4, 25, 4, 32, 56, 89929), auto_now=True),
            preserve_default=False,
        ),
    ]
}}}

Note that it should be `default=datetime.datetime(2014, 4, 25, 4, 32, 56, 89929)` instead."	Bug	closed	Migrations	1.7-beta-1	Release blocker	duplicate			Unreviewed	0	0	0	0	0	0