MSSQL多表查询(一个基表,两个附表求和)问题

[kkk6041]

三个表:
1.学校表(school):id,schoolname,createdate
2.学生表(student):id,username,schoolid,createdate
3.评论表(comment):id,comment,schoolid,createdate

现在想用一条SQL语句获得如下数据(不用存储过程):
select school.id, school.schoolname, count(student.id) as countstudent, count(comment.id) as countcomment from ... where (or ...on) school.id=student.schoolid and school.id=comment.schoolid

请高手赐教,不胜感谢!

[wzy_love_sly]

select a.id, a.schoolname, 
sum(case when b.id is not null then 1 else 0 end ) as '学校数量',
sum(case when b.id is not null then 1 else 0 end ) as '评论数量'
from 学校表 a left join 学生表 b on a.id=b.schoolid
left join 评论表 c on a.id=c.schoolid
group by a.id, a.schoolname

[中国风]

select a.id, a.schoolname, 
count(b.ID) as '学校数量',
count(c.ID) as '评论数量'
from 学校表 a 
left join 学生表 b on a.id=b.schoolid
left join 评论表 c on a.id=c.schoolid
group by a.id, a.schoolname

[zarge]

select id, schoolname, 
    ( select count(*) from student where schoolid = a.id ) as countstudent,
    ( select count(*) from comment where schoolid = a.id ) as countcomment
from school a