mysql 检查日期约束(触发器)

问题描述

很抱歉再次打扰，我在 MySql Maria DB 上是全新的(可能也在触发器上)并希望添加检查功能以确保此表中没有插入过去的日期.我相信Mysql的唯一方法是创建一个触发器.我试图创建一个，但我一直遇到问题.谁能告诉我我在这里做错了什么(也许我需要一杯浓咖啡):

Sorry for disturbing again, I completely new on MySql Maria DB (maybe on trigger as well) and looking to add check function to ensure no past date is inserted in this table.I believe that the only way to do it Mysql is to create a trigger.I have tried to create one and I keep on having problems. Can someone tell me what I am doing wrong here (maybe I need a strong coffee):

CREATE TRIGGER check_date BEFORE INSERT on Event
  FOR EACH ROW
  BEGIN
  if new.date <= now() then
  SIGNAL SQLSTATE '45000' SET MESSAGE_TEXT = 'Event cannot start in the past     event cannot start now. Choose an ulterior date'
end
end if;

请我在终端上.每次系统看到分号时，它都会结束我的查询.因此，我不能有 2 个分号.

Please that i'm on a terminal. Every time the system sees a semicolon it ends my query. I cannot therefore have 2 semicolons.

感谢您的帮助.我希望我足够清楚......

thanks for your help .I hope im clear enough...

推荐答案

查询前需要更改分隔符:

You need to change delimiter before the query:

delimiter //

CREATE TRIGGER check_date BEFORE INSERT on Event
FOR EACH ROW
BEGIN
  IF new.date <= now() THEN
    SIGNAL SQLSTATE '45000'
    SET MESSAGE_TEXT = 'Event cannot start in the past     event cannot start now. Choose an ulterior date';
  END IF;
END;//

delimiter ;

另外，在你 END 为事件(触发器)执行整个代码块之前结束你的 IF 语句

Also, end your IF statement before you END the entire block of code to execute for an event(trigger)

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