Question

我有这个代码用于更新，但如何将其更改为DELETE不更新。这是可能的吗？

update r set r.Status = 'Checked-in' from Reservation r 
inner join GuestInfo g on g.GuestID = r.GuestID 
where g.GuestFName = 'firstname' 
and g.GuestLName = 'lastname' 
and r.RoomNo = '103'

Answer 1

这样的事情应该有效：

delete r from Reservation r 
inner join GuestInfo g on g.GuestID = r.GuestID 
where g.GuestFName = 'firstname' 
and g.GuestLName = 'lastname' 
and r.RoomNo = '103'

Answer 2

Delete from Reservation
where id in 
(select r.id from Reservation r 
inner join GuestInfo g on g.GuestID = r.GuestID 
where g.GuestFName = 'firstname' 
and g.GuestLName = 'lastname' 
and r.RoomNo = '103')

Answer 3

绝对！您只需删除UPDATE部分，然后将关键字更改为DELETE：

delete Reservation
from Reservation r 
    inner join GuestInfo g on g.GuestID = r.GuestID 
where g.GuestFName = 'firstname' 
and g.GuestLName = 'lastname' 
and r.RoomNo = '103'

事实上，这很常见。很多时候，您需要根据条件执行更复杂的DELETE，并且多次 SELECT和UPDATE语句可以非常轻松地< / strong>变成DELETE。事实上，我曾经工作过一次，他们的统治就是：

撰写SELECT语句，然后如果它为您提供了数据，请删除SELECT并将其更改为DELETE - 但仅限于此。

ASP C＃查询删除内连接表

3 个答案: