通過觸發器，使之無法修改某些欄位的數據，同時不影響修改其他欄位。

			DROP TRIGGER IF EXISTS `members`;
			SET @OLD_SQL_MODE=@@SQL_MODE, SQL_MODE='';
			DELIMITER //
			CREATE TRIGGER `members` BEFORE UPDATE ON `members` FOR EACH ROW BEGIN
			set new.name = old.name;
			set new.cellphone = old.cellphone;
			set new.email = old.email;
			set new.password = old.password;
			END//
			DELIMITER ;
			SET SQL_MODE=@OLD_SQL_MODE;
		

再舉一個例子

			CREATE TABLE `account` (
			`id` INT(10) UNSIGNED NOT NULL AUTO_INCREMENT,
			`user` VARCHAR(50) NOT NULL DEFAULT '0',
			`cash` FLOAT NOT NULL DEFAULT '0',
			PRIMARY KEY (`id`)
			)
			COLLATE='utf8_general_ci'
			ENGINE=InnoDB;
		

每一次數據變化新增一條數據

			INSERT INTO `test`.`account` (`user`, `cash`) VALUES ('neo', -10);
			INSERT INTO `test`.`account` (`user`, `cash`) VALUES ('neo', -5);
			INSERT INTO `test`.`account` (`user`, `cash`) VALUES ('neo', 30);
			INSERT INTO `test`.`account` (`user`, `cash`) VALUES ('neo', -20);
		

保護用戶的餘額不被修改

			DROP TRIGGER IF EXISTS `account`;
			SET @OLD_SQL_MODE=@@SQL_MODE, SQL_MODE='';
			DELIMITER //
			CREATE TRIGGER `account` BEFORE UPDATE ON `account` FOR EACH ROW BEGIN
			set new.cash = old.cash;
			END//
			DELIMITER ;
			SET SQL_MODE=@OLD_SQL_MODE;