Fixed #27021 -- Allowed lookup expressions in annotations, aggregations, and QuerySet.filter().

Thanks Hannes Ljungberg and Simon Charette for reviews.

Co-authored-by: Mariusz Felisiak <felisiak.mariusz@gmail.com>

2 files changed, 22 insertions, 3 deletions

diff --git a/django/db/models/sql/query.py b/django/db/models/sql/query.py
index 87be8ea9f0..2412e6ad4e 100644
--- a/django/db/models/sql/query.py
+++ b/django/db/models/sql/query.py
@@ -1262,9 +1262,9 @@ class Query(BaseExpression):
         if hasattr(filter_expr, 'resolve_expression'):
             if not getattr(filter_expr, 'conditional', False):
                 raise TypeError('Cannot filter against a non-conditional expression.')
-            condition = self.build_lookup(
-                ['exact'], filter_expr.resolve_expression(self, allow_joins=allow_joins), True
-            )
+            condition = filter_expr.resolve_expression(self, allow_joins=allow_joins)
+            if not isinstance(condition, Lookup):
+                condition = self.build_lookup(['exact'], condition, True)
             clause = self.where_class()
             clause.add(condition, AND)
             return clause, []
diff --git a/django/db/models/sql/where.py b/django/db/models/sql/where.py
index 2577e1d7a5..5a4da97396 100644
--- a/django/db/models/sql/where.py
+++ b/django/db/models/sql/where.py
@@ -208,6 +208,25 @@ class WhereNode(tree.Node):
         clone.resolved = True
         return clone
 
+    @cached_property
+    def output_field(self):
+        from django.db.models import BooleanField
+        return BooleanField()
+
+    def select_format(self, compiler, sql, params):
+        # Wrap filters with a CASE WHEN expression if a database backend
+        # (e.g. Oracle) doesn't support boolean expression in SELECT or GROUP
+        # BY list.
+        if not compiler.connection.features.supports_boolean_expr_in_select_clause:
+            sql = f'CASE WHEN {sql} THEN 1 ELSE 0 END'
+        return sql, params
+
+    def get_db_converters(self, connection):
+        return self.output_field.get_db_converters(connection)
+
+    def get_lookup(self, lookup):
+        return self.output_field.get_lookup(lookup)
+
 
 class NothingNode:
     """A node that matches nothing."""