我有三張桌子: - 房間:有關房間的信息 - 牀:有關與房間相關的房間中的每張牀的信息(類型,...)ID - 分配:有關分配房間中牀位數量的信息一組(2組在一個房間是可能的)需要多個查詢?
我想與牀位數和分配牀位數列表,在一個房間裏
樣品:
SELECT
COUNT(beds.id) AS beds
FROM rooms
JOIN beds ON rooms.id=beds.roomID
WHERE rooms.id='124'
給出的牀位數在房間裏(8)。
SELECT
SUM(requestsAllocations.bedsAllocated) AS allocated,
from rooms
join requestsAllocations on requestsAllocations.roomID=rooms.id
where rooms.id='124'
給我分配牀的在房間內的數:7(1 + 6)
SELECT
COUNT(beds.id) AS beds,
SUM(requestsAllocations.bedsAllocated) AS allocated
FROM rooms
JOIN requestsAllocations ON requestsAllocations.roomID=rooms.id
JOIN beds ON rooms.id=beds.roomID
WHERE rooms.id='124'
給我:
beds | allocated
----------------
16 | 56
- 16牀(計數兩次由於分配表中的2條記錄)
- 56分配牀位(7 * 8 = 56)
如何查詢以獲得正確的結果?
beds | allocated
----------------
8 | 7
謝謝!