Improved ManyToManyField.through docs.
@@ -1818,6 +1818,13 @@ that control how the relationship functions.
:ref:`extra data with a many-to-many relationship
<intermediary-manytomany>`.
+ .. note::
+
+ If you don't want multiple associations between the same instances, add
+ a :class:`~django.db.models.UniqueConstraint` including the from and to
+ fields. Django's automatically generated many-to-many tables include
+ such a constraint.
+
.. note::
Recursive relationships using an intermediary model and defined as
@@ -1851,7 +1858,9 @@ that control how the relationship functions.
points (i.e. the target model instance).
This class can be used to query associated records for a given model
- instance like a normal model.
+ instance like a normal model::
+
+ Model.m2mfield.through.objects.all()
.. attribute:: ManyToManyField.through_fields
