MySQL database security prevents writing and modifying methods MySQL databases can use triggers to make it impossible to modify the data of certain fields without affecting the modification of other fields.
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;
Another example:
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;
Each data change adds a new data entry.
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);
Protect your balance from modification
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;