Contar el número de filas devueltas por una consulta select

Necesito contar el número de filas que devuelve la siguiente consulta.

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

He tratado de seguir 

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)

Da un mensaje de error en query analyzer que dice lo siguiente:

Msg 102, Nivel 15, Estado 1, Línea 7 Sintaxis incorrecta cerca de ')'.

Author: Avión, 2012-03-30
Source

4 answers

SQL Server requiere que SELECT FROM o JOIN tenga un alias.

Agregue un alias a su subconsulta (en este caso x):

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)  x
 49
Author: JNK,
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2012-03-30 15:18:29

Intente envolver toda su selección entre corchetes, luego ejecute un conteo(*) en ese

select count(*)
from
(
   select m.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
) myNewTable
 9
Author: Mikey Mouse,
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2012-03-30 15:18:50

El error de sintaxis se debe a que falta un alias para la subconsulta: 

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)  mySubQuery  /* Alias */
 5
Author: Diego,
Warning: date(): Invalid date.timezone value 'Europe/Kyiv', we selected the timezone 'UTC' for now. in /var/www/agent_stack/data/www/ajaxhispano.com/template/agent.layouts/content.php on line 61
2012-03-30 15:19:44 
select COUNT(*)
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
 0
Author: Jeremy Pridemore,
Warning: date(): Invalid date.timezone value 'Europe/Kyiv', we selected the timezone 'UTC' for now. in /var/www/agent_stack/data/www/ajaxhispano.com/template/agent.layouts/content.php on line 61
2012-03-30 15:17:50