mysql检查日期约束(触发) [英] mysql check date constraint (trigger)

问题描述

很抱歉再次打扰，我是MySql Maria DB的全新用户(也许也可以在触发器上使用)，并希望添加检查功能以确保在此表中未插入任何过去的日期.我相信，唯一的方法Mysql是创建触发器.我尝试创建一个，但仍然遇到问题.有人可以告诉我我在这里做错了吗(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;

请确保我在码头上.每次系统看到分号时，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.我希望我说得足够清楚...

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

推荐答案

您需要在查询之前更改定界符:

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 ;

此外，在执行事件(触发)的整个代码块之前，请先结束 IF 语句

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

这篇关于mysql检查日期约束(触发)的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！