日期:2014-05-16  浏览次数:20782 次

mysql 触发器实例

测试表1

DROP TABLE IF EXISTS test;                  
CREATE TABLE test (  
  id           bigint(11) unsigned NOT NULL AUTO_INCREMENT,  
  name         varchar(100) NOT NULL DEFAULT '',  
  type         varchar(100),
  create_time  datetime,  
  PRIMARY KEY (ID)  
) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8;  

测试表2

DROP TABLE IF EXISTS test_hisy;                  
CREATE TABLE test_hisy (  
  id           bigint(11) unsigned NOT NULL AUTO_INCREMENT,  
  name         varchar(100) NOT NULL DEFAULT '',  
  type         varchar(100),
  create_time  datetime,
  operation    varchar(100) COMMENT '操作类型',
  PRIMARY KEY (ID)  
) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8;  

insert触发器

表test新增记录后,将type值为“1”的记录同时插入到test_hisy表中(AFTER INSERT:录入后触发, BEFORE INSERT:录入前触发)

DELIMITER //
DROP TRIGGER IF EXISTS t_after_insert_test//
CREATE TRIGGER t_after_insert_test
AFTER INSERT ON test
FOR EACH ROW
BEGIN
    IF new.type='1' THEN
    insert into test_hisy(name, type, create_time, operation) 
    values(new.name, new.type, new.create_time, 'insert');
    END IF;
END;//


update触发器

表test修改时,若type值为“2”则将修改前的记录同时插入到test_hisy表中(AFTER UPDATE:修改后触发, BEFORE UPDATE:修改前触发)

DELIMITER //
DROP TRIGGER IF EXISTS t_before_update_test//
CREATE TRIGGER t_before_update_test
BEFORE UPDATE ON test
FOR EACH ROW
BEGIN
    IF new.type='2' THEN
    insert into test_hisy(name, type, create_time, operation) 
    values(old.name, old.type, old.create_time, 'update');
    END IF;
END;//

delete触发器

表test删除记录前,将删除的记录录入到表test_hisy中(AFTER DELETE:删除后触发, BEFORE DELETE:删除前触发)

DELIMITER //
DROP TRIGGER IF EXISTS t_before_delete_test//
CREATE TRIGGER t_before_delete_test
BEFORE DELETE ON test
FOR EACH ROW
BEGIN
    insert into test_hisy(name, type, create_time, operation) 
    values(old.name, old.type, old.create_time, 'delete');
END;//
注:以上触发器例子中出现的new为修改后的数据, old为修改前的数据