Question

更新包含时间戳的表时，我得到一个奇怪的结果，有人知道为什么会发生这种情况吗，还有其他解决方案吗？我的代码是

SET SQL_SAFE_UPDATES = 0;

create temporary table _peters
(
    order_time TIMESTAMP,
    pickup_time TIMESTAMP,
    item_count INT DEFAULT 0
);

insert _peters (order_time, pickup_time)
      select '2018-10-20T09:00:00.000', '2018-10-20T09:00:00.000'
union select '2018-10-20T10:00:00.000', '2018-10-20T10:00:00.000'
union select '2018-10-20T11:00:00.000', '2018-10-20T11:00:00.000';

update _peters p,
(
    select '2018-10-20T10:00:00.000' as order_time,
           '2018-10-20T10:00:00.000' as pickup_time,
           10 as item_count
) z
set p.item_count = z.item_count, p.pickup_time = z.pickup_time
where p.order_time = z.order_time
and p.pickup_time = z.pickup_time;

select * from _peters;
drop temporary table _peters;

注意

设置p.item_count = z.item_count，p.pickup_time = z.pickup_time

没有“ p.pickup_time = z.pickup_time”，则目标时间戳会损坏，如这些结果所示。

Result of select * from _peters;

任何人都有想法-还是这个错误？谢谢。

Answer 1

这是因为您将字段设置为TIMESTAMP －如果使用了DATETIME，则可以定义任何日期/时间，并且它不会被覆盖。 TIMESTAMP默认为CURRENT_TIMESTAMP

create temporary table _peters
(
    order_time DATETIME,
    pickup_time DATETIME,
    item_count INT DEFAULT 0
);

MySql更新时间戳损坏

1 个答案: