Fix fetch_val for raw queries in Postgres backend

databases/backends/postgres.py

@@ -96,7 +96,7 @@ def __init__(
 
     def __getitem__(self, key: typing.Any) -> typing.Any:
         if len(self._column_map) == 0:  # raw query
-            return self._row[tuple(self._row.keys()).index(key)]
+            return self._row[key if type(key) is int else tuple(self._row.keys()).index(key)]
         elif type(key) is Column:
             idx, datatype = self._column_map_full[str(key)]
         elif type(key) is int:

tests/test_databases.py

@@ -202,6 +202,14 @@ async def test_queries_raw(database_url):
             assert result["text"] == "example2"
             assert result["completed"] == False
 
+            # fetch_val()
+            query = "SELECT completed FROM notes WHERE text = :text"
+            result = await database.fetch_val(query=query, values={"text": "example1"})
+            assert result == True
+            query = "SELECT completed FROM notes WHERE text = :text"
+            result = await database.fetch_val(query=query, values={"text": "example1"}, column="completed")
+            assert result == True
+
             # iterate()
             query = "SELECT * FROM notes"
             iterate_results = []