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导读:例子,实例学习mysql触发器的用法.一,准备二张测试表:1,测试表1
DROP TABLE IF EXISTS test; CREATE TABLE test ( id bigin...
例子,实例学习mysql触发器的用法.MYSQL应用
一,准备二张测试表:
1,测试表1
MYSQL应用
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;
2,测试表2
MYSQL应用
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;
二,mysql触发器实例
1,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)
MYSQL应用
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;//
2,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)
MYSQL应用
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;//
3,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)
MYSQL应用
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;//
备注: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.MYSQL应用
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