Refs #35381 -- Moved JSONNull to django.db.models.expressions.

3 files changed, 30 insertions, 26 deletions

diff --git a/django/db/models/__init__.py b/django/db/models/__init__.py
index b8f95526f7..c5803929c5 100644
--- a/django/db/models/__init__.py
+++ b/django/db/models/__init__.py
@@ -28,6 +28,7 @@ from django.db.models.expressions import (
     ExpressionWrapper,
     F,
     Func,
+    JSONNull,
     OrderBy,
     OuterRef,
     RowRange,
@@ -45,7 +46,7 @@ from django.db.models.fields import __all__ as fields_all
 from django.db.models.fields.composite import CompositePrimaryKey
 from django.db.models.fields.files import FileField, ImageField
 from django.db.models.fields.generated import GeneratedField
-from django.db.models.fields.json import JSONField, JSONNull
+from django.db.models.fields.json import JSONField
 from django.db.models.fields.proxy import OrderWrt
 from django.db.models.indexes import *  # NOQA
 from django.db.models.indexes import __all__ as indexes_all
diff --git a/django/db/models/expressions.py b/django/db/models/expressions.py
index d0e91f13d2..9d3c1241e7 100644
--- a/django/db/models/expressions.py
+++ b/django/db/models/expressions.py
@@ -1233,6 +1233,30 @@ class Value(Expression):
         return self.value
 
 
+@deconstructible(path="django.db.models.JSONNull")
+class JSONNull(Value):
+    """Represent JSON `null` primitive."""
+
+    def __init__(self):
+        from django.db.models import JSONField
+
+        super().__init__(None, output_field=JSONField())
+
+    def __repr__(self):
+        return f"{self.__class__.__name__}()"
+
+    def as_sql(self, compiler, connection):
+        value = self.output_field.get_db_prep_value(self.value, connection)
+        if value is None:
+            value = "null"
+        return "%s", (value,)
+
+    def as_mysql(self, compiler, connection):
+        sql, params = self.as_sql(compiler, connection)
+        sql = "JSON_EXTRACT(%s, '$')"
+        return sql, params
+
+
 class RawSQL(Expression):
     allowed_default = True
 
diff --git a/django/db/models/fields/json.py b/django/db/models/fields/json.py
index cf4f5953a7..ed7b4d26a6 100644
--- a/django/db/models/fields/json.py
+++ b/django/db/models/fields/json.py
@@ -12,7 +12,6 @@ from django.db.models.lookups import (
     PostgresOperatorLookup,
     Transform,
 )
-from django.utils.deconstruct import deconstructible
 from django.utils.deprecation import RemovedInDjango70Warning, django_file_prefixes
 from django.utils.translation import gettext_lazy as _
 
@@ -151,28 +150,6 @@ class JSONField(CheckFieldDefaultMixin, Field):
         )
 
 
-@deconstructible(path="django.db.models.JSONNull")
-class JSONNull(expressions.Value):
-    """Represent JSON `null` primitive."""
-
-    def __init__(self):
-        super().__init__(None, output_field=JSONField())
-
-    def __repr__(self):
-        return f"{self.__class__.__name__}()"
-
-    def as_sql(self, compiler, connection):
-        value = self.output_field.get_db_prep_value(self.value, connection)
-        if value is None:
-            value = "null"
-        return "%s", (value,)
-
-    def as_mysql(self, compiler, connection):
-        sql, params = self.as_sql(compiler, connection)
-        sql = "JSON_EXTRACT(%s, '$')"
-        return sql, params
-
-
 class DataContains(FieldGetDbPrepValueMixin, PostgresOperatorLookup):
     lookup_name = "contains"
     postgres_operator = "@>"
@@ -357,7 +334,9 @@ class JSONExact(lookups.Exact):
         # Treat None lookup values as null.
         if rhs == "%s" and (*rhs_params,) == (None,):
             rhs_params = ("null",)
-        if connection.vendor == "mysql" and not isinstance(self.rhs, JSONNull):
+        if connection.vendor == "mysql" and not isinstance(
+            self.rhs, expressions.JSONNull
+        ):
             func = ["JSON_EXTRACT(%s, '$')"] * len(rhs_params)
             rhs %= tuple(func)
         return rhs, rhs_params
@@ -464,7 +443,7 @@ class JSONIn(ProcessJSONLHSMixin, lookups.In):
         if (
             connection.features.supports_primitives_in_json_field
             and isinstance(self.rhs, expressions.ExpressionList)
-            and JSONNull() in self.rhs.get_source_expressions()
+            and expressions.JSONNull() in self.rhs.get_source_expressions()
         ):
             # Break the lookup into multiple exact lookups combined with OR, as
             # Oracle does not support directly extracting JSON scalar null as a