MySQL數據庫安全之防止撰改的方法

MySQL數據庫可以通過觸發器，使之無法修改某些字段的數據，同時又不會影響修改其他字段。

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);

保護用戶的余額不被修改

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;