add comment on impl for psql of_type

aiidateam · Nov 26, 2024 · ffa0b11 · ffa0b11
1 parent 2189a81
commit ffa0b11
Showing 1 changed file with 3 additions and 0 deletions.
diff --git a/src/aiida/storage/psql_dos/orm/querybuilder/main.py b/src/aiida/storage/psql_dos/orm/querybuilder/main.py
@@ -669,6 +669,9 @@ def cast_according_to_type(path_in_json, value):
             if value in value_types:
                 expr = jsonb_typeof(database_entity) == value
             elif value in null_types:
+                # https://www.postgresql.org/docs/current/functions-json.html
+                # json_typeof('null'::json) → null
+                # json_typeof(NULL::json) IS NULL → t
                 tp = jsonb_typeof(database_entity)
                 expr = or_(tp == 'null', tp.is_(None))
         elif operator == 'like':