Mysql中创建触发器的基本语法如下: CREATE TRIGGER trigger_name trigger_time trigger_event ON table_name FOR EACH ROW BEGIN -- 触发器的执行逻辑 END; 1. 2. 3. 4. 5. 6. trigger_name:触发器的名称,唯一标识触发器。 trigger_time:触发器的执行时机,可以是BEFORE或AFTER。 trigger_event:触发器的事件...
Error: Can't update table 'table2' in stored function/trigger because it is already used by statement which invoked this stored function/trigger. 1. 2. 这个错误的意思就是,在执行修改的时候触发一个触发器,而触发器中会执行另外一个UPDATE语句,会接着触发另一个触发器… 从而形成循环触发,因此执行失败。
“字段列表”中的“customerNumber”列未知,但select语句可以工作,因此我认为触发器有一些错误。使用MYSQL8.0.21 update customers set phone = '2128822470' where customerNumber = 181; select * from customers where customerNumber = 181;
MySQL said: Documentation #1064 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '' at line 6 Subject Views Written By Posted If Exists Trigger syntax ...
MySQL:使用多个if语句触发 mysql triggers 我有一个MySQL触发器,它有条件地(使用IF语句)用另一个表中三列之一的随机值更新两列。当我更改两个条件值中的一个时,两个随机列都会在只应该是一个时得到更新。任何帮助都太好了! DB fiddle帮助解释问题:https://dbfiddle.uk/?rdbms=mysql_8.0&fiddle=d2ad0a29...
create trigger tri_after_insert_cmd after insert on cmd for each row #触发器名称要尽可能详细如例 begin if NEW.success = 'no' then # NEW为mysql对新插入记录的封装名; 如果不用mysql的触发器,可以在自己的应用程序中加if判断 insert into errlog(err_cmd,err_time) values(NEW.cmd,NEW.sub_time...
DELIMITER //CREATE TRIGGER BeforeInsertOrderDetail BEFORE INSERT ON OrderDetailFOR EACH ROWBEGIN DECLARE v_nowCount INT; SELECT Amount INTO v_nowCount FROM Goods WHERE ID = new.GoodsID; IF v_nowCount - new.Amount < 0 THEN -- 由于 MySQL 没有直接抛出异常...
问mysql使用IF NOT NULL作为事务的一部分EN注意：MySQL字段尽量避免NULL，应该指定列为NOT NULL，除非你...
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...
I wanted to try the Triggers in MySQL 5.1 and did the following: CREATE TRIGGER overall_country_stats AFTER INSERT ON tbl_log_rows FOR EACH ROW BEGIN IF EXISTS (SELECT * FROM tbl_overall_country_stats WHERE country=NEW.country) THEN UPDATE tbl_overall_country_stats SET impressions ...