Throw exception if more than 1 job type in config

Author: necnec

pandas/io/gbq.py

@@ -396,6 +396,9 @@ def run_query(self, query, **kwargs):
         }
         config = kwargs.get('config')
         if config is not None:
+            if len(config) != 1:
+                raise ValueError("Only one job type must be specified, "
+                                 "but given {}".format(','.join(config.keys()))
             if 'query' in config:
                 if 'query' in config['query'] and query is not None:
                     raise ValueError("Query statement can't be specified "