# Start transaction
  mysql> START TRANSACTION;

  # IX (intention exclusive lock) on certain rows -- lock until transaction ends (committed)
  mysql> SELECT * FROM Rig WHERE RigID > 251 FOR UPDATE;

  # Do what u want (e.g. update to some cols for the specific rows)
  mysql> UPDATE Rig Set State = 2 where RigID > 251;

  # End transaction with commit (and thus lock will be released after this)
  mysql> COMMIT;