select m.Company_id
from Monitor as m
    inner join Monitor_Request as mr on mr.Company_ID=m.Company_id
    group by m.Company_id
    having COUNT(m.Monitor_id)>=5

我已经尝试过跟随

select COUNT(*) from
(
select m.Company_id
from Monitor as m
    inner join Monitor_Request as mr on mr.Company_ID=m.Company_id
    group by m.Company_id
    having COUNT(m.Monitor_id)>=5)

它在查询分析器中提供了一个错误消息,其中说明如下：

Msg 102,Level 15,State 1,Line 7 Incorrect Syntax near ‘)’.