码迷,mamicode.com
首页 > 其他好文 > 详细

information_schema.triggers 学习

时间:2016-08-28 10:56:49      阅读:125      评论:0      收藏:0      [点我收藏+]

标签:

mysql实例中的每一个trigger 对应到information_schema.triggers 中有一行

 

1、information_schema.triggers 表的常用列:

  1、trigger_catalog          :永远是def

  2、trigger_schema          :trigger 所在的数据库名

  3、event_manipulation        :触发trigger 的事件类型可以是 insert | update | delete

  4、event_object_schema        :trigger 所基于的表所在的数据库名

  5、event_object_table        :trigger 所基于的表名

  6、action_statement         :trigger 内部所包涵的SQL语句

 

2、例子:

drop table if exists t;
drop table if exists t_log;


create table t(
id int auto_increment,
x int,
constraint pk__t__id primary key(id))
engine=innodb
default char set utf8;


create table t_log(
id int auto_increment,
log_time datetime default now(),
constraint pk__t_log__id primary key(id))
engine=innodb
default char set utf8;


delimiter go
create trigger tg__insert__t
before insert
on t
for each row
begin

    insert into t_log(log_time) values(current_timestamp());
end 
go

delimiter ;

查看trigger 信息:

mysql> select * from triggers \G
*************************** 1. row ***************************
           TRIGGER_CATALOG: def
            TRIGGER_SCHEMA: tempdb
              TRIGGER_NAME: tg__insert__t
        EVENT_MANIPULATION: INSERT
      EVENT_OBJECT_CATALOG: def
       EVENT_OBJECT_SCHEMA: tempdb
        EVENT_OBJECT_TABLE: t
              ACTION_ORDER: 0
          ACTION_CONDITION: NULL
          ACTION_STATEMENT: begin

insert into t_log(log_time) values(current_timestamp());
end
        ACTION_ORIENTATION: ROW
             ACTION_TIMING: BEFORE
ACTION_REFERENCE_OLD_TABLE: NULL
ACTION_REFERENCE_NEW_TABLE: NULL
  ACTION_REFERENCE_OLD_ROW: OLD
  ACTION_REFERENCE_NEW_ROW: NEW
                   CREATED: NULL
                  SQL_MODE: STRICT_TRANS_TABLES,NO_ENGINE_SUBSTITUTION
                   DEFINER: root@localhost
      CHARACTER_SET_CLIENT: utf8
      COLLATION_CONNECTION: utf8_general_ci
        DATABASE_COLLATION: latin1_swedish_ci

 

information_schema.triggers 学习

标签:

原文地址:http://www.cnblogs.com/JiangLe/p/5814394.html

(0)
(0)
   
举报
评论 一句话评论(0
登录后才能评论!
© 2014 mamicode.com 版权所有  联系我们:gaon5@hotmail.com
迷上了代码!