diff options
Diffstat (limited to 'docs')
| -rw-r--r-- | docs/ref/models/fields.txt | 16 |
1 files changed, 9 insertions, 7 deletions
diff --git a/docs/ref/models/fields.txt b/docs/ref/models/fields.txt index c83b50ab7e..612949ab4a 100644 --- a/docs/ref/models/fields.txt +++ b/docs/ref/models/fields.txt @@ -43,13 +43,15 @@ If ``True``, Django will store empty values as ``NULL`` in the database. Default is ``False``. Avoid using :attr:`~Field.null` on string-based fields such as -:class:`CharField` and :class:`TextField`. If a string-based field has -``null=True``, that means it has two possible values for "no data": ``NULL``, -and the empty string. In most cases, it's redundant to have two possible values -for "no data;" the Django convention is to use the empty string, not -``NULL``. One exception is when a :class:`CharField` has both ``unique=True`` -and ``blank=True`` set. In this situation, ``null=True`` is required to avoid -unique constraint violations when saving multiple objects with blank values. +:class:`CharField` and :class:`TextField`. The Django convention is to use an +empty string, not ``NULL``, as the "no data" state for string-based fields. If a +string-based field has ``null=False``, empty strings can still be saved for "no +data". If a string-based field has ``null=True``, that means it has two possible +values for "no data": ``NULL``, and the empty string. In most cases, it's +redundant to have two possible values for "no data". One exception is when a +:class:`CharField` has both ``unique=True`` and ``blank=True`` set. In this +situation, ``null=True`` is required to avoid unique constraint violations when +saving multiple objects with blank values. For both string-based and non-string-based fields, you will also need to set ``blank=True`` if you wish to permit empty values in forms, as the |