问题描述

我无法为 MySQL 数据库定义触发器.我想在插入新行之前更改文本字段(在给定条件下).这是我尝试过的:

I have trouble defining a trigger for a MySQL database. I want to change a textfield before inserting a new row (under a given condition). This is what I have tried:

CREATE TRIGGER add_bcc
BEFORE INSERT ON MailQueue
FOR EACH ROW BEGIN
  IF (NEW.sHeaders LIKE "%support@mydomain.com%") THEN
    SET NEW.sHeaders = NEW.sHeaders + "BCC:internal@mydomain.com";
  END IF;
END; 

但我总是收到错误语法错误".我被卡住了，我做错了什么?我正在使用 MySQL 5.0.51a-community

But always I get the error "wrong syntax". I got stuck, what am I doing wrong? I'm using MySQL 5.0.51a-community

顺便说一句:像这样创建一个空的触发器工作正常:

BTW: Creating an empty Trigger like this works fine:

CREATE TRIGGER add_bcc
BEFORE INSERT ON MailQueue
FOR EACH ROW BEGIN
END; 

但这也失败了:

CREATE TRIGGER add_bcc
BEFORE INSERT ON MailQueue 
FOR EACH ROW BEGIN
  IF 1=1 THEN
  END IF; 
END;

这是我第一次使用 stackoverflow.com，所以如果在这里发布一些东西有帮助，我很兴奋:-)

It's my first time to use stackoverflow.com, so I'm very excited if it is helpful to post something here :-)

推荐答案

您需要 更改分隔符 - MySQL 看到第一个;"作为 CREATE TRIGGER 语句的结尾.

You need to change the delimiter - MySQL is seeing the first ";" as the end of the CREATE TRIGGER statement.

试试这个:

/* Change the delimiter so we can use ";" within the CREATE TRIGGER */
DELIMITER $$

CREATE TRIGGER add_bcc
BEFORE INSERT ON MailQueue
FOR EACH ROW BEGIN
  IF (NEW.sHeaders LIKE "%support@mydomain.com%") THEN
    SET NEW.sHeaders = NEW.sHeaders + "BCC:internal@mydomain.com";
  END IF;
END$$
/* This is now "END$$" not "END;" */

/* Reset the delimiter back to ";" */
DELIMITER ;

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