chore: avoid explicit commit if we are in autocommit mode

ibis/backends/mysql/__init__.py

@@ -255,13 +255,19 @@ def drop_database(self, name: str, force: bool = False) -> None:
     def begin(self):
         con = self.con
         cur = con.cursor()
+
+        if not con.autocommit_mode:
+            con.begin()
+
         try:
             yield cur
         except Exception:
-            con.rollback()
+            if not con.autocommit_mode:
+                con.rollback()
             raise
         else:
-            con.commit()
+            if not con.autocommit_mode:
+                con.commit()
         finally:
             cur.close()
 
@@ -279,14 +285,19 @@ def raw_sql(self, query: str | sg.Expression, **kwargs: Any) -> Any:
         con = self.con
         cursor = con.cursor()
 
+        if not con.autocommit_mode:
+            con.begin()
+
         try:
             cursor.execute(query, **kwargs)
         except Exception:
-            con.rollback()
+            if not con.autocommit_mode:
+                con.rollback()
             cursor.close()
             raise
         else:
-            con.commit()
+            if not con.autocommit_mode:
+                con.commit()
             return cursor
 
     # TODO: disable positional arguments