Fixed #34338 -- Allowed customizing code of ValidationError in BaseConstraint and subclasses.

3 files changed, 51 insertions, 5 deletions

diff --git a/docs/ref/contrib/postgres/constraints.txt b/docs/ref/contrib/postgres/constraints.txt
index fcf50b8b5f..abc5e4e4e4 100644
--- a/docs/ref/contrib/postgres/constraints.txt
+++ b/docs/ref/contrib/postgres/constraints.txt
@@ -12,7 +12,7 @@ PostgreSQL supports additional data integrity constraints available from the
 ``ExclusionConstraint``
 =======================
 
-.. class:: ExclusionConstraint(*, name, expressions, index_type=None, condition=None, deferrable=None, include=None, violation_error_message=None)
+.. class:: ExclusionConstraint(*, name, expressions, index_type=None, condition=None, deferrable=None, include=None, violation_error_code=None, violation_error_message=None)
 
     Creates an exclusion constraint in the database. Internally, PostgreSQL
     implements exclusion constraints using indexes. The default index type is
@@ -133,6 +133,16 @@ used for queries that select only included fields
 ``include`` is supported for GiST indexes. PostgreSQL 14+ also supports
 ``include`` for SP-GiST indexes.
 
+``violation_error_code``
+------------------------
+
+.. versionadded:: 5.0
+
+.. attribute:: ExclusionConstraint.violation_error_code
+
+The error code used when ``ValidationError`` is raised during
+:ref:`model validation <validating-objects>`. Defaults to ``None``.
+
 ``violation_error_message``
 ---------------------------
 
diff --git a/docs/ref/models/constraints.txt b/docs/ref/models/constraints.txt
index baaacd8754..f248de0315 100644
--- a/docs/ref/models/constraints.txt
+++ b/docs/ref/models/constraints.txt
@@ -48,7 +48,7 @@ option.
 ``BaseConstraint``
 ==================
 
-.. class:: BaseConstraint(*, name, violation_error_message=None)
+.. class:: BaseConstraint(* name, violation_error_code=None, violation_error_message=None)
 
     Base class for all constraints. Subclasses must implement
     ``constraint_sql()``, ``create_sql()``, ``remove_sql()`` and
@@ -68,6 +68,16 @@ All constraints have the following parameters in common:
 The name of the constraint. You must always specify a unique name for the
 constraint.
 
+``violation_error_code``
+------------------------
+
+.. versionadded:: 5.0
+
+.. attribute:: BaseConstraint.violation_error_code
+
+The error code used when ``ValidationError`` is raised during
+:ref:`model validation <validating-objects>`. Defaults to ``None``.
+
 ``violation_error_message``
 ---------------------------
 
@@ -94,7 +104,7 @@ This method must be implemented by a subclass.
 ``CheckConstraint``
 ===================
 
-.. class:: CheckConstraint(*, check, name, violation_error_message=None)
+.. class:: CheckConstraint(*, check, name, violation_error_code=None, violation_error_message=None)
 
     Creates a check constraint in the database.
 
@@ -121,7 +131,7 @@ ensures the age field is never less than 18.
 ``UniqueConstraint``
 ====================
 
-.. class:: UniqueConstraint(*expressions, fields=(), name=None, condition=None, deferrable=None, include=None, opclasses=(), violation_error_message=None)
+.. class:: UniqueConstraint(*expressions, fields=(), name=None, condition=None, deferrable=None, include=None, opclasses=(), violation_error_code=None, violation_error_message=None)
 
     Creates a unique constraint in the database.
 
@@ -242,6 +252,22 @@ creates a unique index on ``username`` using ``varchar_pattern_ops``.
 
 ``opclasses`` are ignored for databases besides PostgreSQL.
 
+``violation_error_code``
+------------------------
+
+.. versionadded:: 5.0
+
+.. attribute:: UniqueConstraint.violation_error_code
+
+The error code used when ``ValidationError`` is raised during
+:ref:`model validation <validating-objects>`. Defaults to ``None``.
+
+This code is *not used* for :class:`UniqueConstraint`\s with
+:attr:`~UniqueConstraint.fields` and without a
+:attr:`~UniqueConstraint.condition`. Such :class:`~UniqueConstraint`\s have the
+same error code as constraints defined with :attr:`.Field.unique` or in
+:attr:`Meta.unique_together <django.db.models.Options.constraints>`.
+
 ``violation_error_message``
 ---------------------------
 
diff --git a/docs/releases/5.0.txt b/docs/releases/5.0.txt
index 14e767cfd8..84689f223d 100644
--- a/docs/releases/5.0.txt
+++ b/docs/releases/5.0.txt
@@ -78,7 +78,10 @@ Minor features
 :mod:`django.contrib.postgres`
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-* ...
+* The new :attr:`~.ExclusionConstraint.violation_error_code` attribute of
+  :class:`~django.contrib.postgres.constraints.ExclusionConstraint` allows
+  customizing the ``code`` of ``ValidationError`` raised during
+  :ref:`model validation <validating-objects>`.
 
 :mod:`django.contrib.redirects`
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
@@ -182,6 +185,13 @@ Models
   and :meth:`.QuerySet.aupdate_or_create` methods allows specifying a different
   field values for the create operation.
 
+* The new ``violation_error_code`` attribute of
+  :class:`~django.db.models.BaseConstraint`,
+  :class:`~django.db.models.CheckConstraint`, and
+  :class:`~django.db.models.UniqueConstraint` allows customizing the ``code``
+  of ``ValidationError`` raised during
+  :ref:`model validation <validating-objects>`.
+
 Requests and Responses
 ~~~~~~~~~~~~~~~~~~~~~~