diff options
Diffstat (limited to 'docs')
| -rw-r--r-- | docs/ref/checks.txt | 2 | ||||
| -rw-r--r-- | docs/ref/models/constraints.txt | 22 | ||||
| -rw-r--r-- | docs/releases/5.0.txt | 3 |
3 files changed, 26 insertions, 1 deletions
diff --git a/docs/ref/checks.txt b/docs/ref/checks.txt index 9e1381c31f..a208114596 100644 --- a/docs/ref/checks.txt +++ b/docs/ref/checks.txt @@ -408,6 +408,8 @@ Models expression and won't be validated during the model ``full_clean()``. * **models.W046**: ``<database>`` does not support comments on tables (``db_table_comment``). +* **models.W047**: ``<database>`` does not support unique constraints with + nulls distinct. Security -------- diff --git a/docs/ref/models/constraints.txt b/docs/ref/models/constraints.txt index 4ed5b65d46..efe63a8ac1 100644 --- a/docs/ref/models/constraints.txt +++ b/docs/ref/models/constraints.txt @@ -131,7 +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_code=None, violation_error_message=None) +.. class:: UniqueConstraint(*expressions, fields=(), name=None, condition=None, deferrable=None, include=None, opclasses=(), nulls_distinct=None, violation_error_code=None, violation_error_message=None) Creates a unique constraint in the database. @@ -254,6 +254,26 @@ creates a unique index on ``username`` using ``varchar_pattern_ops``. ``opclasses`` are ignored for databases besides PostgreSQL. +``nulls_distinct`` +------------------ + +.. versionadded:: 5.0 + +.. attribute:: UniqueConstraint.nulls_distinct + +Whether rows containing ``NULL`` values covered by the unique constraint should +be considered distinct from each other. The default value is ``None`` which +uses the database default which is ``True`` on most backends. + +For example:: + + UniqueConstraint(name="ordering", fields=["ordering"], nulls_distinct=False) + +creates a unique constraint that only allows one row to store a ``NULL`` value +in the ``ordering`` column. + +``nulls_distinct`` is ignored for databases besides PostgreSQL 15+. + ``violation_error_code`` ------------------------ diff --git a/docs/releases/5.0.txt b/docs/releases/5.0.txt index e4c1eac1d9..815fb062b4 100644 --- a/docs/releases/5.0.txt +++ b/docs/releases/5.0.txt @@ -361,6 +361,9 @@ Models set the primary key on each model instance when the ``update_conflicts`` parameter is enabled (if the database supports it). +* The new :attr:`.UniqueConstraint.nulls_distinct` attribute allows customizing + the treatment of ``NULL`` values on PostgreSQL 15+. + Pagination ~~~~~~~~~~ |