创建MySQL触发器的语法介绍
MySQL触发器是MySQL数据库非常重要的部分,下文对创建MySQL触发器及删除MySQL触发器作了详细的介绍,希望对您有所帮助。
MySQL触发器是MySQL数据库非常重要的部分,下文对创建MySQL触发器及删除MySQL触发器作了详细的介绍,希望对您有所帮助。
1、创建Mysql触发器:
语法:
CREATE TRIGGER trigger_name trigger_time trigger_event ON tbl_name
FOR EACH ROW
BEGIN
trigger_stmt
END;
CREATE TRIGGER trigger_name trigger_time trigger_event ON tbl_name FOR EACH ROW BEGIN trigger_stmt END;大写的为关键字
trigger_name:Mysql触发器的名字,我常用的命名规则t_name_tableName_(b|a)(i|u|d),t:触发器标识,name:英文名,,tableName:表名,
b(BEFORE):标识是触发事件之前,
a(AFTER):标识触发事件之后,
i(insert): 标识insert事件,
u(update):标识update事件,
d(delete):标识delete事件;
trigger_time:触发时间(BEFORE或AFTER)
trigger_event:事件名(insert或update或delete)
tbl_name:表名(必须是永久性表)
trigger_stmt:执行语句(可以是复合语名),使用别名OLD和NEW,能够引用与触发程序相关的表中的列。
2、删除Mysql解发器
语法:
DROP TRIGGER [schema_name.]trigger_name;
注意:以上操作均需SUPER权限
MySQL触发器的创建与删除
下面的文章主要描述的是MySQL触发器的正确创建步骤,MySQL触发器的删除,你如果对MySQL触发器的正确创建步骤,MySQL触发器的删除有兴趣的话你就可以点击以下的文章进行观看了。
1、创建MySQL触发器:
语法:
CREATE TRIGGER trigger_name trigger_time trigger_event ON tbl_name
FOR EACH ROW
BEGIN
trigger_stmt
END;
CREATE TRIGGER trigger_name trigger_time trigger_event ON tbl_name
FOR EACH ROW
BEGIN
trigger_stmt
END;
例子
CREATE TRIGGER SetUserHome after insert ON users
FOR EACH ROW
BEGIN
update `users` set homeLocationX = 128,
homeLocationY=128, homeLocationZ=30
where uuid = NEW.uuid
END
以上的例子是错误的, 让本表进行触发时进行更新会让程序进入死循环。
更多详情见请继续阅读下一页的精彩内容:
相关阅读:
利用MySQL触发器高性能造数据
MySQL触发器的使用
MySQL触发器管理
MySQL触发器处理本表数据
Linux下MySQL触发器设置

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