Fixed #31685 -- Added support for updating conflicts to QuerySet.bulk_create().

Thanks Florian Apolloner, Chris Jerdonek, Hannes Ljungberg, Nick Pope,
and Mariusz Felisiak for reviews.

2 files changed, 30 insertions, 4 deletions

diff --git a/docs/ref/models/querysets.txt b/docs/ref/models/querysets.txt
index e0d4311b15..60360ee163 100644
--- a/docs/ref/models/querysets.txt
+++ b/docs/ref/models/querysets.txt
@@ -2155,7 +2155,7 @@ exists in the database, an :exc:`~django.db.IntegrityError` is raised.
 ``bulk_create()``
 ~~~~~~~~~~~~~~~~~
 
-.. method:: bulk_create(objs, batch_size=None, ignore_conflicts=False)
+.. method:: bulk_create(objs, batch_size=None, ignore_conflicts=False, update_conflicts=False, update_fields=None, unique_fields=None)
 
 This method inserts the provided list of objects into the database in an
 efficient manner (generally only 1 query, no matter how many objects there
@@ -2198,9 +2198,17 @@ where the default is such that at most 999 variables per query are used.
 
 On databases that support it (all but Oracle), setting the ``ignore_conflicts``
 parameter to ``True`` tells the database to ignore failure to insert any rows
-that fail constraints such as duplicate unique values. Enabling this parameter
-disables setting the primary key on each model instance (if the database
-normally supports it).
+that fail constraints such as duplicate unique values.
+
+On databases that support it (all except Oracle and SQLite < 3.24), setting the
+``update_conflicts`` parameter to ``True``, tells the database to update
+``update_fields`` when a row insertion fails on conflicts. On PostgreSQL and
+SQLite, in addition to ``update_fields``, a list of ``unique_fields`` that may
+be in conflict must be provided.
+
+Enabling the ``ignore_conflicts`` or ``update_conflicts`` parameter disable
+setting the primary key on each model instance (if the database normally
+support it).
 
 .. warning::
 
@@ -2217,6 +2225,12 @@ normally supports it).
 
     Support for the fetching primary key attributes on SQLite 3.35+ was added.
 
+.. versionchanged:: 4.1
+
+    The ``update_conflicts``, ``update_fields``, and ``unique_fields``
+    parameters were added to support updating fields when a row insertion fails
+    on conflict.
+
 ``bulk_update()``
 ~~~~~~~~~~~~~~~~~
 
diff --git a/docs/releases/4.1.txt b/docs/releases/4.1.txt
index b6112fe29e..8fc23e6141 100644
--- a/docs/releases/4.1.txt
+++ b/docs/releases/4.1.txt
@@ -232,6 +232,10 @@ Models
   in order to reduce the number of failed requests, e.g. after database server
   restart.
 
+* :meth:`.QuerySet.bulk_create` now supports updating fields when a row
+  insertion fails uniqueness constraints. This is supported on MariaDB, MySQL,
+  PostgreSQL, and SQLite 3.24+.
+
 Requests and Responses
 ~~~~~~~~~~~~~~~~~~~~~~
 
@@ -298,6 +302,14 @@ backends.
 * ``DatabaseIntrospection.get_key_columns()`` is removed. Use
   ``DatabaseIntrospection.get_relations()`` instead.
 
+* ``DatabaseOperations.ignore_conflicts_suffix_sql()`` method is replaced by
+  ``DatabaseOperations.on_conflict_suffix_sql()`` that accepts the ``fields``,
+  ``on_conflict``, ``update_fields``, and ``unique_fields`` arguments.
+
+* The ``ignore_conflicts`` argument of the
+  ``DatabaseOperations.insert_statement()`` method is replaced by
+  ``on_conflict`` that accepts ``django.db.models.constants.OnConflict``.
+
 Dropped support for MariaDB 10.2
 --------------------------------