mysql - SQL - 日期字段限制(<=今天)

Question

我有一个表格，其中包含成员(member)加入俱乐部时输入的日期。该列是沼泽标准，类型为 DATE。不需要时间。

基本上，我正在尝试找到一种 future 不可能的方式？

Answer 1

您可以使用触发器。下面是一个功能齐全的测试示例:

create table t(signup_date date not null);

delimiter //
create trigger ins_check_date before insert on t
  for each row
  begin
    if (new.signup_date > current_date()) then
      signal sqlstate '45000' set message_text = 'Date cannot be in the future';
    end if;
  end//

create trigger up_check_date before update on t
  for each row
  begin
    if (new.signup_date > current_date()) then
      signal sqlstate '45000' set message_text = 'Date cannot be in the future';
    end if;
  end//



delimiter ;

insert into t values (current_date());
insert into t values (current_date() - interval 1 day);
insert into t values (current_date() - interval 2 day);
insert into t values (current_date() + interval 1 day);

select * from t;
update t set signup_date = signup_date - interval 1 month 
where signup_date = current_date() - interval 1 day;

update t set signup_date = signup_date + interval 1 month 
where signup_date = current_date();
select * from t;