[DO NOT MERGE] SNOW-295953: rows_affected_proposal

src/snowflake/connector/cursor.py

@@ -418,6 +418,10 @@ def __init__(
         self._log_max_query_length = connection.log_max_query_length
         self._inner_cursor: SnowflakeCursorBase | None = None
         self._prefetch_hook = None
+        self._stats_data: dict[str, int] | None = (
+            None  # Stores stats from response for DML operations
+        )
+
         self._rownumber: int | None = None
 
         self.reset()
@@ -454,6 +458,26 @@ def _description_internal(self) -> list[ResultMetadataV2]:
     def rowcount(self) -> int | None:
         return self._total_rowcount if self._total_rowcount >= 0 else None
 
+    @property
+    def stats(self) -> QueryResultStats | None:
+        """Returns detailed rows affected statistics for DML operations.
+
+        Returns a NamedTuple with fields:
+        - num_rows_inserted: Number of rows inserted
+        - num_rows_deleted: Number of rows deleted
+        - num_rows_updated: Number of rows updated
+
+        Returns None on each position if no DML stats are available.
+        """
+        if self._stats_data is None:
+            return QueryResultStats(None, None, None, None)
+        return QueryResultStats(
+            num_rows_inserted=self._stats_data.get("numRowsInserted", None),
+            num_rows_deleted=self._stats_data.get("numRowsDeleted", None),
+            num_rows_updated=self._stats_data.get("numRowsUpdated", None),
+            num_dml_duplicates=self._stats_data.get("numDmlDuplicates", None),
+        )
+
     @property
     def rownumber(self) -> int | None:
         return self._rownumber if self._rownumber >= 0 else None
@@ -1201,6 +1225,10 @@ def _init_result_and_meta(self, data: dict[Any, Any]) -> None:
         self._rownumber = -1
         self._result_state = ResultState.VALID
 
+        # Extract stats object if available (for DML operations like CTAS, INSERT, UPDATE, DELETE)
+        self._stats_data = data.get("stats", None)
+        logger.debug(f"Execution DML stats: {self.stats}")
+
         # don't update the row count when the result is returned from `describe` method
         if is_dml and "rowset" in data and len(data["rowset"]) > 0:
             updated_rows = 0
@@ -2007,3 +2035,17 @@ def __getattr__(name):
         )
         return None
     raise AttributeError(f"module {__name__!r} has no attribute {name!r}")
+
+
+class QueryResultStats(NamedTuple):
+    """
+    Statistics for rows affected by a DML operation.
+    None value expresses particular statistic being unknown - not returned by the backend service.
+
+    Added in the first place to expose DML data of CTAS statements - SNOW-295953
+    """
+
+    num_rows_inserted: int | None = None
+    num_rows_deleted: int | None = None
+    num_rows_updated: int | None = None
+    num_dml_duplicates: int | None = None

test/integ/test_connection.py

@@ -1063,7 +1063,7 @@ def test_client_fetch_threads_setting(conn_cnx):
 @pytest.mark.skipolddriver
 @pytest.mark.parametrize("disable_request_pooling", [True, False])
 def test_ocsp_and_rest_pool_isolation(conn_cnx, disable_request_pooling):
-    """Each connection’s SessionManager is isolated; OCSP picks the right one."""
+    """Each connection's SessionManager is isolated; OCSP picks the right one."""
     from snowflake.connector.ssl_wrap_socket import get_current_session_manager
 
     #
@@ -1892,3 +1892,86 @@ def test_snowflake_version():
     assert re.match(
         version_pattern, conn.snowflake_version
     ), f"snowflake_version should match pattern 'x.y.z', but got '{conn.snowflake_version}'"
+
+
+@pytest.mark.skipolddriver
+def test_ctas_stats(conn_cnx):
+    """Test that cursor.rowcount and cursor.stats work for CTAS operations."""
+    with conn_cnx() as conn:
+        with conn.cursor() as cur:
+            cur.execute(
+                "create temp table test_ctas_stats (col1 int) as select col1 from values (1), (2), (3) as t(col1)"
+            )
+            assert (
+                cur.rowcount == 1
+            ), f"Expected rowcount 1 for CTAS, got {cur.rowcount}"
+            # stats should contain the details as a NamedTuple
+            assert cur.stats is not None, "stats should not be None for CTAS"
+            assert (
+                cur.stats.num_rows_inserted == 3
+            ), f"Expected num_rows_inserted=3, got {cur.stats.num_rows_inserted}"
+            assert cur.stats.num_rows_deleted == 0
+            assert cur.stats.num_rows_updated == 0
+            assert cur.stats.num_dml_duplicates == 0
+
+
+@pytest.mark.skipolddriver
+def test_create_view_stats(conn_cnx):
+    """Test that cursor.stats returns None fields for VIEW operations."""
+    with conn_cnx() as conn:
+        with conn.cursor() as cur:
+            cur.execute(
+                "create temp view test_view_stats as select col1 from values (1), (2), (3) as t(col1)"
+            )
+            assert (
+                cur.rowcount == 1
+            ), f"Expected rowcount 1 for VIEW, got {cur.rowcount}"
+            # VIEW operations don't return DML stats, all fields should be None
+            assert cur.stats is not None
+            assert cur.stats.num_rows_inserted is None
+            assert cur.stats.num_rows_deleted is None
+            assert cur.stats.num_rows_updated is None
+            assert cur.stats.num_dml_duplicates is None
+
+
+@pytest.mark.skipolddriver
+def test_cvas_separate_cursors_stats(conn_cnx):
+    """Test cursor.stats with CVAS in separate cursor from the one used for CTAS of the table."""
+    with conn_cnx() as conn:
+        with conn.cursor() as cur:
+            cur.execute(
+                "create temp table test_table (col1 int) as select col1 from values (1), (2), (3) as t(col1)"
+            )
+        with conn.cursor() as cur:
+            cur.execute("create temp view test_view as select col1 from test_table")
+            assert (
+                cur.rowcount == 1
+            ), "Due to old behaviour we should keep rowcount equal to 1 - as the number of rows returned by the backend"
+            # VIEW operations don't return DML stats
+            assert cur.stats is not None
+            assert cur.stats.num_rows_inserted is None
+            assert cur.stats.num_rows_deleted is None
+            assert cur.stats.num_rows_updated is None
+            assert cur.stats.num_dml_duplicates is None
+
+
+@pytest.mark.skipolddriver
+def test_cvas_one_cursor_stats(conn_cnx):
+    """Test cursor.stats with CVAS in the same cursor - make sure it's cleaned up after usage."""
+    with conn_cnx() as conn:
+        with conn.cursor() as cur:
+            cur.execute(
+                "create temp table test_ctas_stats (col1 int) as select col1 from values (1), (2), (3) as t(col1)"
+            )
+            cur.execute(
+                "create temp view test_view as select col1 from test_ctas_stats"
+            )
+            assert (
+                cur.rowcount == 1
+            ), "Due to old behaviour we should keep rowcount equal to 1 - as the number of rows returned by the backend"
+            # VIEW operations don't return DML stats
+            assert cur.stats is not None
+            assert cur.stats.num_rows_inserted is None
+            assert cur.stats.num_rows_deleted is None
+            assert cur.stats.num_rows_updated is None
+            assert cur.stats.num_dml_duplicates is None