mysql> select * from books;+----+--------------------------------------+---------------+-----------+| id | title | author | available |+----+--------------------------------------+---------------+-----------+| 1 | The Hitchhiker's Guide to the Galaxy | Douglas Adams | 1 |+----+--------------------------------------+---------------+-----------+1 row in set (0.00 sec)mysql> START TRANSACTION;Query OK, 0 rows affected (0.00 sec)mysql> UPDATE books SET available = 0;Query OK, 1 row affected (0.00 sec)Rows matched: 1 Changed: 1 Warnings: 0mysql> SELECT available FROM books;+-----------+| available |+-----------+| 0 |+-----------+1 row in set (0.00 sec)mysql> ROLLBACK;Query OK, 0 rows affected, 1 warning (0.00 sec)mysql> SELECT available FROM books;+-----------+| available |+-----------+| 0 |+-----------+1 row in set (0.00 sec)mysql>