Edits

Author: WaVEV

django_mongodb_backend/query.py

@@ -132,11 +132,11 @@ def join(self, compiler, connection, pushed_expression=None):
 
     parent_template = "parent__field__"
 
-    def _get_reroot_replacements(expressions):
-        if not expressions:
+    def _get_reroot_replacements(expression):
+        if not expression:
             return None
         columns = []
-        for expr in expressions.leaves():
+        for expr in expression.leaves():
             # Determine whether the column needs to be transformed or rerouted
             # as part of the subquery.
             for hand_side in ["lhs", "rhs"]: