fix(db-engine-spec): execute oracle DML statement bug in sqllab (apac…

…he#10706)

* fix execute oracle DML statement bug in sqllab

when i execute oracle sql statements like update in SQLLAB, get "oracle error: not a query" error. 

Refer https://www.python.org/dev/peps/pep-0249/, superset old version use
`cursor.description` ，because this attribute will be None for operations that do not return rows or if the cursor has not had an operation invoked via the .execute*() method yet.

* Apply suggestions from code review

Co-authored-by: Ville Brofeldt <33317356+villebro@users.noreply.github.com>

* Update oracle.py

* Update oracle.py

* Update oracle.py

* Apply suggestions from code review

Co-authored-by: Ville Brofeldt <33317356+villebro@users.noreply.github.com>

* Update oracle.py

* Update superset/db_engine_specs/oracle.py

Co-authored-by: Ville Brofeldt <33317356+villebro@users.noreply.github.com>

Co-authored-by: Ville Brofeldt <33317356+villebro@users.noreply.github.com>

superset/db_engine_specs/oracle.py

@@ -15,7 +15,7 @@
 # specific language governing permissions and limitations
 # under the License.
 from datetime import datetime
-from typing import Optional
+from typing import Any, List, Optional, Tuple
 
 from superset.db_engine_specs.base import BaseEngineSpec, LimitMethod
 from superset.utils import core as utils
@@ -57,3 +57,16 @@ def epoch_to_dttm(cls) -> str:
     @classmethod
     def epoch_ms_to_dttm(cls) -> str:
         return "TO_DATE('1970-01-01','YYYY-MM-DD')+(1/24/60/60/1000)*{col}"
+
+    @classmethod
+    def fetch_data(
+        cls, cursor: Any, limit: Optional[int] = None
+    ) -> List[Tuple[Any, ...]]:
+        """
+        :param cursor: Cursor instance
+        :param limit: Maximum number of rows to be returned by the cursor
+        :return: Result of query
+        """
+        if not cursor.description:
+            return []
+        return super().fetch_data(cursor, limit)