其中:trigger_time是触发器的触发事件,可以为before(在检查约束前触发)或after(在检查约束后触发);trigger_event是触发器的触发事件,包括insert、update和delete,可以使用old和new来引用触发器中发生变化的记录内容。 需要注意的: 1)需注意对同一个表的相同触发时间(after/before)的相同触发事件(insert/update/delete)...
Hi, I wonder if its possible to use an 'after insert' to update the same table that the trigger is used for and if so, how? I want field_B to get the auto_incremented value of field_A if field_B isnt set in the insert statement....
UPDATE, DELETE) and timing (BEFORE or AFTER). In other words, there could be at most one trigger for every pair (action, timing). It means that a user couldn’t assign for example two BEFORE INSERT triggers for the same table t1. To workaround this restriction and allow se...
使用INSERT语句:只能使用NEW临时表 使用DELETE语句:只能使用OLD临时表 3.创建触发器 CREATE TRIGGER触发器名称触发时机(BEFORE|AFTER)事件(INSERT|UPDATE|DELETE) ON表名称 FOR EACH ROW BEGIN 语句1; 语句2; 语句3; END 说明: 触发时机:指在更新、删除、插入之前BEFORE或之后AFTER ...
TRIGGER trigger_name BEFORE | AFTER INSERT|UPDATE|DELETE ON table_name FOR EACH ROW trigger_stmt。 通过触发器可以实现一些不支持的特性,比如CHECK约束,物化视图,高级复制,审计等特性。比如买东西,每次都是减的,但是如果用户输入了一个负数,就变成加了。这个时候就可以通过触发器来完成这个判断了。
triggertime trigger_event ON tbl_nameFOR EACH ROW trigger_stmt 1. 2. 3. 4. 5. 创建触发器 trigger_name:标识触发器名称,用户自行指定 trigger_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...
#首先先创建一张表;CREATE TABLE `t` ( `a` int(11) NOT NULL AUTO_INCREMENT, `b` varchar(20) DEFAULT NULL, PRIMARY KEY (`a`), KEY `b` (`b`)) ENGINE=InnoDB AUTO_INCREMENT=300 DEFAULT CHARSET=utf8#插入三条数据:mysql> insert into t (b) values ('aa');Query OK, 1 row affected...
CREATE[DEFINER=user]TRIGGERtrigger_nametrigger_timetrigger_eventONtbl_nameFOREACHROW[trigger_order]trigger_bodytrigger_time: {BEFORE|AFTER}trigger_event: {INSERT|UPDATE|DELETE}trigger_order: {FOLLOWS|PRECEDES}other_trigger_name This statement creates a new trigger. A trigger is a named database obje...
Description: When there is an UPDATE and an INSERT trigger on same table, and both triggers perform an INSERT into a second table which has an auto_inc column, replication fails with a DUP KEY error on the UPDATE statement if the transactions are committed in a different order than the ...
Action Time: After Event: Insert update a_players set NEW.wpSlug = concat(lower(NEW.nameFirst),'-',lower(NEW.nameLast)) I'm getting this error: Can't update table 'a_players' in stored function/trigger because it is already used by statement which invoked this stored function/trigger....