fix rowcount (#26)

* fix rowcount

Author: koxudaxi

pydataapi/dbapi.py

@@ -130,7 +130,7 @@ def execute(
         )
         rows: List[List] = getattr(result, '_rows')
         self._rows = rows
-        self._rowcount = len(rows)
+        self._rowcount = len(rows) or result.number_of_records_updated
         return self
 
     def executemany(

pydataapi/pydataapi.py

@@ -174,8 +174,8 @@ def __init__(self, response: Dict):
         super().__init__(response.get('generatedFields', []))
 
     @property
-    def number_of_records_updated(self) -> Optional[int]:
-        return self._response.get('numberOfRecordsUpdated')
+    def number_of_records_updated(self) -> int:
+        return self._response.get('numberOfRecordsUpdated', 0)
 
     @property
     def headers(self) -> List[str]: