如何离开连接数？

Question

select DISTINCT(cctv_id), cctv.[name] from points_cctv left join cctv on points_cctv.[cctv_id] = cctv.[id] 

我想统计points_cctv中的记录数，其中points_cctv.[cctv_id] = cctv.[id]并在上面的查询中显示为附加列。当我插入count(points_cctv.[cctv_id])它只会给我一行。

Answer 1

select cctv_id, cctv.[name], count(cctv_id) 
from points_cctv left join cctv on points_cctv.[cctv_id] = cctv.[id] 
group by cctv_id, cctv.name