Ticket #25718: json_null.patch

django/contrib/postgres/fields/jsonb.py

@@ -64 +64 @@
 JSONField.register_lookup(lookups.HasKey)
 JSONField.register_lookup(lookups.HasKeys)
 JSONField.register_lookup(lookups.HasAnyKeys)
+JSONField.register_lookup(lookups.JSONIsNull)
+JSONField.register_lookup(lookups.JSONExact)
 
 
 class KeyTransform(Transform):

django/contrib/postgres/lookups.py

@@ -1 +1 @@
 from django.db.models import Lookup, Transform
+from django.db.models.lookups import IsNull, Exact
 
 
 class PostgresSimpleLookup(Lookup):
@@ -43 +44 @@
     bilateral = True
     lookup_name = 'unaccent'
     function = 'UNACCENT'
+
+
+class JSONIsNull(IsNull):
+
+    def as_sql(self, compiler, connection):
+        if isinstance(self.lhs, Transform):
+            sql, params = compiler.compile(self.lhs)
+            if self.rhs:
+                return "%s = 'null'" % sql, params
+            else:
+                return "%s != 'null'" % sql, params
+        else:
+            return super(JSONIsNull, self).as_sql(compiler, connection)
+
+
+class JSONExact(Exact):
+
+    def process_rhs(self, compiler, connection):
+        result = super(JSONExact, self).process_rhs(compiler, connection)
+        if result == ('%s', [None]):
+            return "'null'", []
+        return result

django/db/models/sql/query.py

@@ -981 +981 @@
         # Interpret '__exact=None' as the sql 'is NULL'; otherwise, reject all
         # uses of None as a query value.
         if value is None:
-            if lookups[-1] not in ('exact', 'iexact'):
-                raise ValueError("Cannot use None as a query value")
-            lookups[-1] = 'isnull'
-            value = True
+            # Some transformed lookup
+            if lookups[-1] not in self.query_terms:
+                lookups.append('exact')
+            else:
+                if lookups[-1] not in ('exact', 'iexact'):
+                    raise ValueError("Cannot use None as a query value")
+                lookups[-1] = 'isnull'
+                value = True
         elif hasattr(value, 'resolve_expression'):
             pre_joins = self.alias_refcount.copy()
             value = value.resolve_expression(self, reuse=can_reuse, allow_joins=allow_joins)
@@ -1191 +1195 @@
         clause.add(condition, AND)
 
         require_outer = lookup_type == 'isnull' and value is True and not current_negated
-        if current_negated and (lookup_type != 'isnull' or value is False):
+        if current_negated and (lookup_type != 'isnull' or value is False) and value is not None:
             require_outer = True
             if (lookup_type != 'isnull' and (
                     self.is_nullable(targets[0]) or

tests/postgres_tests/test_json.py

@@ -116 +116 @@
             [self.objs[6]]
         )
 
+    def test_deep_lookup_isnull(self):
+        self.assertSequenceEqual(
+            JSONModel.objects.filter(field__j__isnull=True),
+            [self.objs[8]]
+        )
+
+    def test_deep_lookup_isnull_exclude(self):
+        obj = JSONModel.objects.create(field={'j': 1})
+        self.assertSequenceEqual(
+            JSONModel.objects.exclude(field__j__isnull=True),
+            [obj]
+        )
+
+    def test_deep_lookup_none_value(self):
+        self.assertSequenceEqual(
+            JSONModel.objects.filter(field__j=None),
+            [self.objs[8]]
+        )
+
+    def test_deep_lookup_none_value_exclude(self):
+        obj = JSONModel.objects.create(field={'j': 1})
+        self.assertSequenceEqual(
+            JSONModel.objects.exclude(field__j=None),
+            [obj]
+        )
+
+    def test_deep_lookup_not_isnull(self):
+        self.assertSequenceEqual(
+            JSONModel.objects.filter(field__l__isnull=False),
+            [self.objs[10]]
+        )
+
     def test_exact_complex(self):
         self.assertSequenceEqual(
             JSONModel.objects.filter(field__exact={'a': 'b', 'c': 1}),