使用MySQL触发器将所有表更改记录到辅助表

Question

我有一张桌子:

CREATE TABLE `data_table` (
`data_id` INT NOT NULL AUTO_INCREMENT PRIMARY KEY ,
`field1` INT NOT NULL ,
`field2` INT NOT NULL ,
`field3` INT NOT NULL
) ENGINE = MYISAM ;

我会记录任何机会到field1,2或3:

CREATE TABLE `data_tracking` (
`tracking_id` INT NOT NULL AUTO_INCREMENT PRIMARY KEY ,
`data_id` INT NOT NULL ,
`field` VARCHAR( 50 ) NOT NULL ,
`old_value` INT NOT NULL ,
`new_value` INT NOT NULL ,
`modified` DATETIME NOT NULL
) ENGINE = MYISAM ; 

我正在使用MySQL 5,我想创建一个触发器.我想在data_table更新后随时在data_tracking中插入一个新行,并记录旧的/更新的值,以及更改的字段.我尝试了以下没有任何成功.

DELIMITER $$

DROP TRIGGER `update_data `$$

CREATE TRIGGER `update_data` AFTER UPDATE on `data_table`
FOR EACH ROW
BEGIN
    IF (NEW.field1 != OLD.field1) THEN
        INSERT INTO data_tracking set old_value = OLD.field1, new_value = NEW.field1, field = "field1";
    END IF;
END$$

DELIMITER ;

它在插入行上给出了一个错误,我不太清楚应该是什么语法,或者我是否正确地采用这种方法.任何帮助,将不胜感激.谢谢.

Answer 1

插入语法是

INSERT INTO table (columns_list) VALUES (values_list)

所以你的插入看起来像这样(我不是MySQL专家,但你可以适合查询):

INSERT INTO data_tracking 
(`data_id` , `field` , `old_value` , `new_value` , `modified` ) 
VALUES 
(NEW.data_id, 'field1', OLD.field, NEW.field, CURRENT_DATETIME());

并重复它对field2和field3的变化

我认为这将是完全触发器,请尝试:

DELIMITER $$

DROP TRIGGER `update_data `$$

CREATE TRIGGER `update_data` AFTER UPDATE on `data_table`
FOR EACH ROW
BEGIN
    IF (NEW.field1 != OLD.field1) THEN
        INSERT INTO data_tracking 
            (`data_id` , `field` , `old_value` , `new_value` , `modified` ) 
        VALUES 
            (NEW.data_id, "field1", OLD.field1, NEW.field1, NOW());
    END IF;
    IF (NEW.field2 != OLD.field2) THEN
        INSERT INTO data_tracking 
            (`data_id` , `field` , `old_value` , `new_value` , `modified` ) 
        VALUES 
            (NEW.data_id, "field2", OLD.field2, NEW.field2, NOW());
    END IF;
    IF (NEW.field3 != OLD.field3) THEN
        INSERT INTO data_tracking 
            (`data_id` , `field` , `old_value` , `new_value` , `modified` ) 
        VALUES 
            (NEW.data_id, "field3", OLD.field3, NEW.field3, NOW());
    END IF;
END$$

DELIMITER ;