Question

 Select * from HotelPerson 
 Where RoomID IN (select ID from HotelRoom Where BookingID = 36 )

 Select * from HotelCancelationPolicy 
 Where RoomID IN (select ID from HotelRoom Where BookingID = 36 )

如何将这两个查询合并为1个查询？

Answer 1

使用UNION获取两个表中所有行的不同元素或UNION ALL

 Select * from HotelPerson 
 Where RoomID IN (select ID from HotelRoom Where BookingID = 36 )
 UNION ALL
 Select * from HotelCancelationPolicy 
 Where RoomID IN (select ID from HotelRoom Where BookingID = 36 )

Answer 2

我想你想加入这两个表：

    select * 
      from HotelPerson hp
inner join HotelCancelationPolicy hcp
        on hp.RoomId = hcp.RoomId
     where hp.RoomID IN (select ID 
                           from HotelRoom 
                          where BookingID = 36 )

Answer 3

这将为您提供一个表中两个表的所有列。

SELECT * 
FROM HotelPerson A, HotelCancelationPolicy B
WHERE A.RoomID = B.RoomID
AND A.RoomID IN (SELECT ID FROM HotelRoom WHERE BookingID = 36)

如何使用子查询将这些查询合并为1

3 个答案: