mysql - 在 MySQL 中创建触发器时出错

Question

我是我的 sql 的初学者，我遇到了一个错误

#1064 - 您的 SQL 语法有错误；检查与您的 MySQL 服务器版本相对应的手册，以获取在 '@nissue INT DEFAULT 0; 附近使用的正确语法；set @nissue := (set issue_id from Codes where code' at line 5

对于代码

DELIMITER $$
CREATE TRIGGER ai_SMS
    AFTER INSERT ON SMS
    FOR EACH ROW 
BEGIN
       DECLARE @nissue INT DEFAULT 0;
       set @nissue := (set issue_id from Codes where code=NEW.msgbody);
 IF ( EXISTS(SELECT * FROM SMS_fltr AS s INNER JOIN Persons AS  p ON s.sender=p.mobile_number WHERE  s.numissue=@nissue and s.sender=NEW.sender))
       THEN
              UPDATE SMS_fltr set time=NEW.time ,code=NEW.msgbody where  numissue=@nissue and sender=NEW.sender;

       ELSE

              INSERT into SMS_fltr (sender,time,code,numissue) VAUES (NEW.sender,NEW.time,NEW.code,nissue);
       END IF
END$$
DELIMITER ;

我正在尝试为表创建触发器。

任何人都可以告诉我犯了什么错误以及解决方案是什么？

Answer 1

建议#1：不要声明它

DELIMITER $$
CREATE TRIGGER ai_SMS
    AFTER INSERT ON SMS
    FOR EACH ROW 
BEGIN
       set @nissue := (set issue_id from Codes where code=NEW.msgbody);
 IF ( EXISTS(SELECT * FROM SMS_fltr AS s INNER JOIN Persons AS  p ON s.sender=p.mobile_number WHERE  s.numissue=@nissue and s.sender=NEW.sender))
       THEN
              UPDATE SMS_fltr set time=NEW.time ,code=NEW.msgbody where  numissue=@nissue and sender=NEW.sender;

       ELSE

              INSERT into SMS_fltr (sender,time,code,numissue) VAUES (NEW.sender,NEW.time,NEW.code,nissue);
       END IF
END$$
DELIMITER ;

建议 #2：将其声明为常规变量

DELIMITER $$
CREATE TRIGGER ai_SMS
    AFTER INSERT ON SMS
    FOR EACH ROW 
BEGIN
       DECLARE nissue INT DEFAULT 0;
       set nissue := (set issue_id from Codes where code=NEW.msgbody);
 IF ( EXISTS(SELECT * FROM SMS_fltr AS s INNER JOIN Persons AS  p ON s.sender=p.mobile_number WHERE  s.numissue=@nissue and s.sender=NEW.sender))
       THEN
              UPDATE SMS_fltr set time=NEW.time ,code=NEW.msgbody where  numissue=@nissue and sender=NEW.sender;

       ELSE

              INSERT into SMS_fltr (sender,time,code,numissue) VAUES (NEW.sender,NEW.time,NEW.code,nissue);
       END IF
END$$
DELIMITER ;

试试看 ！！！