以下是MariaDB中create trigger的语法:MySQL不支持or replace和if not exists子句。 CREATE [OR REPLACE] TRIGGER [IF NOT EXISTS] trigger_name { BEFORE | AFTER } { INSERT | UPDATE | DELETE } ON tbl_name FOR EACH ROW trigger_body 触发器只能建立在永久表上,不能建立在视图和临时表上。MySQL/MariaD...
CREATE[DEFINER=user]TRIGGER[IFNOTEXISTS]trigger_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...
4CREATE[OR REPLACE]TRIGGER[IF NOT EXISTS]trigger_name{BEFORE|AFTER} {INSERT|UPDATE|DELETE}ONtbl_nameFOREACHROWtrigger_body 触发器只能建立在永久表上,不能建立在视图和临时表上。MySQL/MariaDB中的触发器只支持行级触发器(即每行都触发一次触发器),不支持数据库级别和服务器级别的触发器。MySQL/MariaDB中...
CREATE TRIGGER <触发器名称>--触发器必须有名字,最多64个字符,可能后面会附有分隔符.它和MySQL中其他对象的命名方式基本相象. { BEFORE | AFTER }--触发器有执行的时间设置:可以设置为事件发生前或后。 { INSERT | UPDATE | DELETE }--同样也能设定触发的事件:它们可以在执行insert、update或delete的过程中...
可能遇到的问题 2.1如果你在触发器里面对刚刚插入的数据进行了 insert/update, 会造成循环的调用. ...: create trigger test before update on test for each row set NEW.updateTime = NOW(); END 2.2如果你在触发器中对操作表的其他行进行操作...because it is already used by statement which invoked th...
(MySQL 8.0.29 and later:)CREATE PROCEDURE IF NOT EXISTS,CREATE FUNCTION IF NOT EXISTS, orCREATE TRIGGER IF NOT EXISTS, if successful, is written in its entirety to the binary log (including theIF NOT EXISTSclause), whether or not the statement raised a warning because the object (procedure...
create trigger f on tbl instead of delete as insert into Logs... IF UPDATE(列名) 检查是否更新了某一列,用于 insert 或 update,不能用于 delete。例: create trigger f on tbl for update as if update(status) or update(title) sql_statement --更新了 status 或 title 列 ...
create trigger 触发器名 before|after 触发事件 on 表名 for each row begin 执行语句列表 end; 1. 2. 3. 4. 5. 2.2 触发器操作实例 首先进行数据准备,定义两个表user与user_logs,分别记录用户注册信息和用户操作日志。希望当user发生变化时,user_logs自动发生变化(通过触发器实现)。数据准备相关代码如下: ...
in MySQL 5.0 DROP FUNCTION IF EXISTS - implemented in MySQL 5.0 CREATE USER IF NOT EXISTS - added in MySQL 5.7 DROP USER IF EXISTS - added in MySQL 5.7 CREATE PROCEDURE IF NOT EXISTS - to be done CREATE FUNCTION IF NOT EXISTS - to be done CREATE TRIGGER IF NOT EXISTS - to be done...