diff --git a/google/cloud/bigquery/dbapi/_helpers.py b/google/cloud/bigquery/dbapi/_helpers.py index 69694c98c..beb3c5e71 100644 --- a/google/cloud/bigquery/dbapi/_helpers.py +++ b/google/cloud/bigquery/dbapi/_helpers.py @@ -276,7 +276,7 @@ def decorate_public_methods(klass): """Apply ``_raise_on_closed()`` decorator to public instance methods. """ for name in dir(klass): - if name.startswith("_"): + if name.startswith("_") and name != "__iter__": continue member = getattr(klass, name) diff --git a/google/cloud/bigquery/dbapi/cursor.py b/google/cloud/bigquery/dbapi/cursor.py index ee09158d8..7e5449718 100644 --- a/google/cloud/bigquery/dbapi/cursor.py +++ b/google/cloud/bigquery/dbapi/cursor.py @@ -365,6 +365,10 @@ def setinputsizes(self, sizes): def setoutputsize(self, size, column=None): """No-op, but for consistency raise an error if cursor is closed.""" + def __iter__(self): + self._try_fetch() + return iter(self._query_data) + def _format_operation_list(operation, parameters): """Formats parameters in operation in the way BigQuery expects. diff --git a/tests/unit/test_dbapi_cursor.py b/tests/unit/test_dbapi_cursor.py index 0f44e3895..8ca4e9b6c 100644 --- a/tests/unit/test_dbapi_cursor.py +++ b/tests/unit/test_dbapi_cursor.py @@ -178,6 +178,7 @@ def test_raises_error_if_closed(self): "fetchone", "setinputsizes", "setoutputsize", + "__iter__", ) for method in method_names: @@ -611,6 +612,29 @@ def test_executemany_w_dml(self): self.assertIsNone(cursor.description) self.assertEqual(cursor.rowcount, 12) + def test_is_iterable(self): + from google.cloud.bigquery import dbapi + + connection = dbapi.connect( + self._mock_client(rows=[("hello", "there", 7), ("good", "bye", -3)]) + ) + cursor = connection.cursor() + cursor.execute("SELECT foo, bar, baz FROM hello_world WHERE baz < 42;") + + rows_iter = iter(cursor) + + row = next(rows_iter) + self.assertEqual(row, ("hello", "there", 7)) + row = next(rows_iter) + self.assertEqual(row, ("good", "bye", -3)) + self.assertRaises(StopIteration, next, rows_iter) + + self.assertEqual( + list(cursor), + [], + "Iterating again over the same results should produce no rows.", + ) + def test__format_operation_w_dict(self): from google.cloud.bigquery.dbapi import cursor