LOCK TABLE TableName IN SHARE MODE; LOCK TABLE TableName IN SHARE ROW EXCLUSIVE MODE; LOCK TABLE TableName IN ROW EXCLUSIVE MODE; LOCK TABLE TableName IN EXCLUSIVE MODE;

• 来准确在锁定行而不能更新行。禁止的操作:拥有行级排它锁的事务不允许其它事务有除共享锁外的其它形式的锁加在同一张表上或更新该表。即下面的语句是不被允许的