如何简化这个SQL查询？

Question

update Room set Selected = 1 where Room_ID = 
(select Room_ID from Room_Rev where Rev_ID = 
(select Rev_ID from Room_Rev where Room_ID = 'ROM0001'
and (Start_Date<='2015-03-20' and End_Date>'2015-03-20')))

有人可以帮我简化此查询吗？

我想从Room_Rev中选择许多Room_ID，其中相同的Rev_ID与Room_ID =＆＃39; ROM0001＆＃39;，而不是所有Room_ID将用于更新所选 Room和Room_Rev是一对多的关系

Answer 1

您可以使用以下联接：

update r
set r.Selected = 1
from Room r 
inner join Room_Rev rr on r.Room_ID = rr.Room_ID
where rr.Room_ID = 'ROM0001'
and (rr.Start_Date<='2015-03-20' and rr.End_Date>'2015-03-20')

Answer 2

在join中使用Update...Select：

update Room set Selected = 1 
from  
Room join Room_Rev rr on Room.Room_ID = rr.Room_ID and Room.Room_ID='ROM0001'
and Room.Start_Date<='2015-03-20' and Room.End_Date>'2015-03-20'

或使用where exists：

update Room set Selected = 1 
where exisis (select Rev_ID from Room_Rev where Room_ID = 'ROM0001')
and Room_ID='ROM0001'
and (Start_Date<='2015-03-20' and End_Date>'2015-03-20')