去哪里放哪里？

Question

我有以下查询：

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，但我想补充的现场（场sites.id）中进行选择。我总是得到错误：“您的SQL语法有错误;请检查手册...”

谢谢！

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

它是这样的”

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

参考MYSQL Docs更多细节

所以你的情况这将是这样的：。

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

试试这个：

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