Django datetime migration error
Question: I don't think anything in my model has changed. I have reverted it back to
times when it was all fully functional and I still get the following errors.

There are my models:

    
    
    class UserProfile(models.Model):
        # This line is required. Links UserProfile to a User model instance.
        user = models.OneToOneField(User)
    
        # The additional attributes we wish to include.
        website = models.URLField(blank=True)
        picture = models.ImageField(upload_to='profile_images', blank=True)
    
    
        # Override the __unicode__() method to return out something meaningful!
        def __unicode__(self):
            return self.user.username
    
    
    # Could create more post classes, or introduce foreign keys. Unsure as of now.
    class Post(models.Model):
        title = models.CharField(max_length = 140)
        body = models.TextField()
        date = models.DateTimeField(blank=True)
    
        INTRODUCTION = 'I'
        STORIES = 'S'
        CATEGORY_CHOICES = (
            (STORIES, 'Stories'),  # Variable name and display value
            (INTRODUCTION, 'Introduce Yourself'),
        )
    
        category = models.CharField(max_length=1,
                                    choices=CATEGORY_CHOICES,
                                    default=INTRODUCTION)
    
    
        def __unicode__(self):
            return self.title
    
    
    class Photo(models.Model):
        title = models.CharField(max_length = 140)
        photo = models.ImageField(upload_to='user_images', blank=True, null=True)
        date = models.DateTimeField(blank=True)
    
        description = models.TextField()
    
        def __unicode__(self):
            return self.title
    

Upon running manage.py migrate I am confronted with the following error.
Having checked the other answers, it seems it was something to do with
datetime being used incorrectly but even if I remove date and the DateTime
field altogether the error still persists. Does anyone have any ideas?

Thank very much for your help.

    
    
    Operations to perform:
      Apply all migrations: contenttypes, admin, sessions, auth, blog
    Running migrations:
      Applying blog.0007_auto_20141201_0034...Traceback (most recent call last):
      File "manage.py", line 10, in <module>
        execute_from_command_line(sys.argv)
      File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/django/core/management/__init__.py", line 385, in execute_from_command_line
        utility.execute()
      File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/django/core/management/__init__.py", line 377, in execute
        self.fetch_command(subcommand).run_from_argv(self.argv)
      File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/django/core/management/base.py", line 288, in run_from_argv
        self.execute(*args, **options.__dict__)
      File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/django/core/management/base.py", line 338, in execute
        output = self.handle(*args, **options)
      File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/django/core/management/commands/migrate.py", line 160, in handle
        executor.migrate(targets, plan, fake=options.get("fake", False))
      File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/django/db/migrations/executor.py", line 63, in migrate
        self.apply_migration(migration, fake=fake)
      File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/django/db/migrations/executor.py", line 97, in apply_migration
        migration.apply(project_state, schema_editor)
      File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/django/db/migrations/migration.py", line 107, in apply
        operation.database_forwards(self.app_label, schema_editor, project_state, new_state)
      File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/django/db/migrations/operations/fields.py", line 37, in database_forwards
        field,
      File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/django/db/backends/sqlite3/schema.py", line 160, in add_field
        self._remake_table(model, create_fields=[field])
      File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/django/db/backends/sqlite3/schema.py", line 74, in _remake_table
        self.effective_default(field)
      File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/django/db/backends/schema.py", line 183, in effective_default
        default = field.get_db_prep_save(default, self.connection)
      File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/django/db/models/fields/__init__.py", line 627, in get_db_prep_save
        prepared=False)
      File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/django/db/models/fields/__init__.py", line 1286, in get_db_prep_value
        value = self.get_prep_value(value)
      File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/django/db/models/fields/__init__.py", line 1269, in get_prep_value
        value = super(DateTimeField, self).get_prep_value(value)
      File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/django/db/models/fields/__init__.py", line 1171, in get_prep_value
        return self.to_python(value)
      File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/django/db/models/fields/__init__.py", line 1228, in to_python
        parsed = parse_datetime(value)
      File "/Library/Frameworks/Python.framework/Versions/3.4/lib/python3.4/site-packages/django/utils/dateparse.py", line 70, in parse_datetime
        match = datetime_re.match(value)
    TypeError: expected string or buffer
    

Here is 'blog.0007...' migration that seems to be failing. To clarify what is
going on I was attempting to add a few attributes in order to tell who posted,
and at what time etc. Clearly something is not going according to plan..

    
    
    # -*- coding: utf-8 -*-
    from __future__ import unicode_literals
    
    from django.db import models, migrations
    from django.conf import settings
    
    
    class Migration(migrations.Migration):
    
        dependencies = [
            migrations.swappable_dependency(settings.AUTH_USER_MODEL),
            ('blog', '0006_auto_20141201_0027'),
        ]
    
        operations = [
            migrations.AddField(
                model_name='post',
                name='created_by',
                field=models.ForeignKey(default=0, related_name='created_by', to=settings.AUTH_USER_MODEL),
                preserve_default=False,
            ),
            migrations.AddField(
                model_name='post',
                name='created_on',
                field=models.DateTimeField(default=0, auto_now_add=True),
                preserve_default=False,
            ),
            migrations.AddField(
                model_name='post',
                name='edited_by',
                field=models.ForeignKey(default=0, related_name='edited_by', to=settings.AUTH_USER_MODEL),
                preserve_default=False,
            ),
            migrations.AddField(
                model_name='post',
                name='edited_on',
                field=models.DateTimeField(default=0, auto_now=True),
                preserve_default=False,
            ),
            migrations.AddField(
                model_name='post',
                name='published',
                field=models.BooleanField(default=None),
                preserve_default=True,
            ),
        ]
    


Answer: I think the problem is here:

    
    
    DateTimeField(default=0...)
    

Either use `None` or a `datetime` object

