trigger_time:标识触发时机,取值为 BEFORE 或 AFTER; trigger_event:标识触发事件,取值为 INSERT、UPDATE 或 DELETE; tbl_name:标识建立触发器的表名,即在哪张表上建立触发器; trigger_stmt:触发器程序体,可以是一句SQL语句,或者用 BEGIN 和 END 包含的多条语句。 由此可见,可以建立6种触发器,即:BEFORE INSERT...
触发器(trigger)是一个特殊的存储过程,它的执行不是由程序调用, Mysql触发器与存储器 mysql 数据库 sql 存储过程 MySQL referencing 创建触发器 mysql的触发器 1、触发器(trigger)的定义触发器是与表事件相关的特殊存储过程,它的执行不由程序调用,也非手工启动,而是由事件触发、激活从而实现执行。简单来说,触发器...
对的，MYSQL不用referencing，百度可以搜索MYSQL5中文手册呀，说得非常非常清楚，我粘贴到下面：21.1. CREATE TRIGGER语法 CREATE TRIGGER trigger_name trigger_time trigger_event ON tbl_name FOR EACH ROW trigger_stmt 触发程序是与表有关的命名数据库对象，当表上出现特定事件时，将激活该对象。触发...
1.定义触发器 create trigger 触发器名 before|after 触发事件 on 表名 referencing new|old row|table as 变量 解释:将这行|表的旧|新的命名为变量名 for each row|statement [when 触发条件] 触发动作体 如果省略[when 触发条件]则触发动作体在触发器激活后立即执行 row 行级触发器 statement 语句级触发器...
I'm trying to create a generic audit trigger I can add to all my user tables. This is relatively easy to do. But my issue is that I want to make it Dynamic in that if a new column is added to a table or taken away (product still in early development) I want the trigger to ...
-- 前置更新触发器CREATE TRIGGER `tr_af_update` BEFORE UPDATE ON `f2` FOR EACH ROW set new.mark = new.f1_r1;mysql-(ytt_fk/3305)->insert into f2 values (1,10,5);Query OK, 1 row affected (0.00 sec)mysql-(ytt_fk/3305)->select * from f2;+---+---+---+| id | f1_r1 |...
I have a situation where I'm trying to create a trigger that as soon as I manually update a specific row in table1 regarding the game number, I'd like it to compare/evaluate the changes that have been updated in table1(liveResult) towards the existing values from ...
Setting foreign_key_checks to 1 does not trigger a scan of the existing table data. Therefore, rows added to the table while foreign_key_checks=0 will not be verified for consistency. 当FOREIGN_KEY_CHECKS设置为0时,外键约束会被忽略,而当FOREIGN_KEY_CHECKS设置为1时不会触发约束检查。
另一种查询触发器命令: show triggers; 删除触发器命令: drop trigger trigger_name; 六、删除添加索引 建立降序索引语法: create index 索引名 on 表名(字段名 desc); 注:desc换成asc则是升序索引。 删除索引语法: drop index 索引名; 但是我的MySQL8.0不支持这种删除索引方式,下面是从student表中删除索引snam...
bool create_trigger (THD *thd, String *binlog_create_trigger_stmt, bool if_not_exists, bool &already_exists) Create trigger for table. More... bool process_triggers (THD *thd, enum_trigger_event_type event, enum_trigger_action_time_type action_time, bool old_row_is_record1) Execute ...