Fixed #8802 -- Documented MySQL's usage of 1/0 instead of True/False for model

BooleanFields.


git-svn-id: http://code.djangoproject.com/svn/django/trunk@8910 bcc190cf-cafb-0310-a4f2-bffc1f526a37

2 files changed, 23 insertions, 0 deletions

diff --git a/docs/ref/databases.txt b/docs/ref/databases.txt
index 66bb836ccc..e484dfd29e 100644
--- a/docs/ref/databases.txt
+++ b/docs/ref/databases.txt
@@ -228,6 +228,16 @@ storage engine, you have a couple of options.
 
 .. _AlterModelOnSyncDB: http://code.djangoproject.com/wiki/AlterModelOnSyncDB
 
+Boolean fields in Django
+-------------------------
+
+Since MySQL doesn't have a direct ``BOOLEAN`` column type, Django uses a
+``TINYINT`` column with values of ``1`` and ``0`` to store values for the
+:class:`~django.db.models.BooleanField` model field. Refer to the documentation
+of that field for more details, but usually this won't be something that will
+matter unless you're printing out the field values and are expecting to see
+``True`` and ``False.``.
+
 
 .. _oracle-notes:
 
diff --git a/docs/ref/models/fields.txt b/docs/ref/models/fields.txt
index 8412f02d73..97ca83aa52 100644
--- a/docs/ref/models/fields.txt
+++ b/docs/ref/models/fields.txt
@@ -296,6 +296,19 @@ A true/false field.
 
 The admin represents this as a checkbox.
 
+.. admonition:: MySQL users..
+
+    A boolean field in MySQL is stored as a ``TINYINT`` column with a value of
+    either 0 or 1 (most databases have a proper ``BOOLEAN`` type instead). So,
+    for MySQL, only, when a ``BooleanField`` is retrieved from the database
+    and stored on a model attribute, it will have the values 1 or 0, rather
+    than ``True`` or ``False``. Normally, this shouldn't be a problem, since
+    Python guarantees that ``1 == True`` and ``0 == False`` are both true.
+    Just be careful if you're writing something like ``obj is True`` when
+    ``obj`` is a value from a boolean attribute on a model. If that model was
+    constructed using the ``mysql`` backend, the "``is``" test will fail.
+    Prefer an equality test (using "``==``") in cases like this.
+
 ``CharField``
 -------------