Question

大家好我正在尝试合并两个查询：

SELECT DISTINCT name,$price 
FROM room 
JOIN room_booking ON room.room_id=room_booking.room_id 
WHERE date_booked<>'$us_date' AND capacity>=$partySize

和

SELECT DISTINCT room_id
FROM room_booking
WHERE room_id NOT IN 
    (SELECT DISTINCT room_id
     FROM room_booking
     WHERE date_booked = '$date'
    )

合并上述内容的最佳方法是什么，以便最终查询检查room_booking表中不存在的日期，并在房间表超出给定容量时从房间表中提取相关信息。

Answer 1

这应该完成文本中描述的工作（但我不确定date_booked<>'$us_date'应该做什么）：

select name, price
from room
where capacity >= $partySize
and room_id not in 
  (select room_id
   from room_booking
   where date_booked = '$date'
  )

Answer 2

尝试以下列方式合并：

SELECT DISTINCT name,$price 
FROM room JOIN room_booking ON room.room_id=room_booking.room_id 
WHERE date_booked<>'$us_date' AND capacity>=$partySize AND room_booking.room_id IN (SELECT DISTINCT room_id
                                                                                    FROM room_booking
                                                                                    WHERE room_id NOT IN 
                                                                                        (SELECT DISTINCT room_id
                                                                                         FROM room_booking
                                                                                         WHERE date_booked = '$date'
                                                                                    ));

Answer 3

也许

SELECT DISTINCT name,$price 
FROM room 
JOIN room_booking ON room.room_id=room_booking.room_id 
WHERE date_booked<>'$us_date' AND capacity>=$partySize 
AND date_booked <> '$date'

或者您是否也想列出所有room_id？然后将room_id添加到选择列表中。在这种情况下你可以删除distinct，因为我认为room_id是唯一的

合并两个SQL查询

3 个答案: