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Code Issues 32 Releases Wiki Activity

[3.1.x] Improved ManyToManyField.through docs.

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Backport of e7fa8aff43 from master
This commit is contained in:
Adam Johnson
2020-07-10 14:27:31 +01:00
committed by Mariusz Felisiak
parent e63644d37b
commit 32e22f0531
1 changed files with 10 additions and 1 deletions
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docs/ref/models/fields.txt
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@@ -1837,6 +1837,13 @@ that control how the relationship functions.
:ref:`extra data with a many-to-many relationship :ref:`extra data with a many-to-many relationship
<intermediary-manytomany>`. <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:: .. note::
Recursive relationships using an intermediary model and defined as Recursive relationships using an intermediary model and defined as
@@ -1870,7 +1877,9 @@ that control how the relationship functions.
points (i.e. the target model instance). points (i.e. the target model instance).
This class can be used to query associated records for a given model 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 .. attribute:: ManyToManyField.through_fields