      :attr:`~Field.null`
          If ``True``, Django will store empty values as ``NULL`` in the database.
          Default is ``False``.
  
      :attr:`~ieldblank`
  
          If ``True``, the field is allowed to be blank. Default is ``False``.
      
          Note that this is different than :attr:`~Field.null`.
          :attr:`~Field.null` is purely database-related, whereas
 
</s> remove     :attr:`~Field.primary_key``
 </s> add     :attr:`~Field.primary_key` </s> remove relationship also has access to a ``Manager`` object, but that ``Manager``
represents a single object, rather than a collection of objects::
 </s> add relationship also has access to a :class:`~django.db.models.Manager` object, but
that :class:`~django.db.models.Manager` represents a single object, rather than
a collection of objects:: </s> remove and the groups of which they are a member, so you could use a ManyToManyField
to represent this relationship. However, there is a lot of detail about the
membership that you might want to collect, such as the date at which the person
joined the group.
 </s> add and the groups of which they are a member, so you could use a
:class:`~django.db.models.ManyToManyField` to represent this relationship.
However, there is a lot of detail about the membership that you might want to 
collect, such as the date at which the person joined the group. </s> remove ``ManyToManyField`` using the ``through`` argument to point to the model
 </s> add :class:`~django.db.models.ManyToManyField` using the 
:attr:`through <ManyToManyFields.through>` argument to point to the model </s> remove mixing and matching pizzas and toppings, a standard ``ManyToManyField``
is all you need. However, sometimes you may need to associate data with the
relationship between two models. 
 </s> add mixing and matching pizzas and toppings, a standard :class:`~django.db.models.ManyToManyField` is all you need. However, sometimes
you may need to associate data with the relationship between two models.
    :attr:`~Field.blank`
      :attr:`~Field.null`
          If ``True``, Django will store empty values as ``NULL`` in the database.
          Default is ``False``.
  
    :attr:`~Field.blank`
  
          If ``True``, the field is allowed to be blank. Default is ``False``.
      
          Note that this is different than :attr:`~Field.null`.
          :attr:`~Field.null` is purely database-related, whereas
keep keep keep keep replace keep keep keep keep keep
 Fixed a handful of typo/markup problems in the docs. Patch from Daniel Roseman.


git-svn-id: http://code.djangoproject.com/svn/django/trunk@8540 bcc190cf-cafb-0310-a4f2-bffc1f526a37 
docs/topics/db/models.txt