去哪裏放哪裏？

Question

我有以下查詢：

select 
sites.denomination, 
rooms.floor, 
rooms.number, 
(count(beds.id) - sum(if(beds.state<0,1,0))) as active 
from rooms 
join sites on rooms.site_id = sites.id 
join beds on rooms.id = beds.room_id group by beds.room_id 
order by 
    sites.denomination, 
    rooms.floor 

它工作得非常好，但我想補充的現場（場sites.id）中進行選擇。我總是得到錯誤：「您的SQL語法有錯誤;請檢查手冊...」

謝謝！

Answer 1

select 
sites.denomination, 
rooms.floor, 
rooms.number, 
(count(beds.id) - sum(if(beds.state<0,1,0))) as active 
from rooms 
join sites on rooms.site_id = sites.id 
join beds on rooms.id = beds.room_id 
where sites.id = ... 
group by beds.room_id 
order by 
    sites.denomination, 
    rooms.floor 

Answer 2

它是這樣的」

select... 
from...joins 
where.... 
group by.. 
having..... 
order by... 
limit.... 

參考MYSQL Docs更多細節

所以你的情況這將是這樣的：。

select 
sites.denomination, 
rooms.floor, 
rooms.number, 
(count(beds.id) - sum(if(beds.state<0,1,0))) as active 
from rooms 
join sites on rooms.site_id = sites.id 
join beds on rooms.id = beds.room_id 
where ...........//Add your where condition here 
group by beds.room_id 
order by 
    sites.denomination, 
    rooms.floor 

Answer 3

SELECT 
sites.denomination, 
rooms.floor, 
rooms.number, 
(COUNT(beds.id) - SUM(if(beds.state<0,1,0))) AS active 
FROM rooms 
JOIN sites ON rooms.site_id = sites.id 
JOIN beds ON rooms.id = beds.room_id 
//your WHERE should be here 
GROUP BY beds.room_id 
ORDER BY 
    sites.denomination, 
    rooms.floor 

Answer 4

試試這個：

select 
sites.denomination, 
rooms.floor, 
rooms.number, 
(count(beds.id) - sum(if(beds.state<0,1,0))) as active 
from rooms 
inner join sites on rooms.site_id = sites.id 
inner join beds on rooms.id = beds.room_id 
where **instruction** 
group by beds.room_id 
order by 
sites.denomination, 
rooms.floor