Add deferrable argument to unique constraint (#472)

django-stubs/db/models/__init__.pyi

@@ -132,6 +132,7 @@ from . import signals as signals
 from .constraints import (
     BaseConstraint as BaseConstraint,
     CheckConstraint as CheckConstraint,
+    Deferrable as Deferrable,
     UniqueConstraint as UniqueConstraint,
 )
 

django-stubs/db/models/constraints.pyi

@@ -1,3 +1,4 @@
+import enum
 from typing import Any, Optional, Sequence, Tuple, Type, TypeVar
 
 from django.db.backends.base.schema import BaseDatabaseSchemaEditor
@@ -6,6 +7,10 @@ from django.db.models.query_utils import Q
 
 _T = TypeVar("_T", bound="BaseConstraint")
 
+class Deferrable(enum.Enum):
+    DEFERRED: str
+    IMMEDIATE: str
+
 class BaseConstraint:
     name: str
     def __init__(self, name: str) -> None: ...
@@ -24,4 +29,7 @@ class CheckConstraint(BaseConstraint):
 class UniqueConstraint(BaseConstraint):
     fields: Tuple[str]
     condition: Optional[Q]
-    def __init__(self, *, fields: Sequence[str], name: str, condition: Optional[Q] = ...): ...
+    deferrable: Optional[Deferrable]
+    def __init__(
+        self, *, fields: Sequence[str], name: str, condition: Optional[Q] = ..., deferrable: Optional[Deferrable] = ...
+    ) -> None: ...