表大致如下：
Gender Section
M 1
M 1
F 1
F 2
M 2
M 1
M 2
F 3
M 2
M 3
F 3
....
我用
select section, count(*) as MaleNum from table
group by section
having Gender = 'M '
求每个班的男生数量，可是好像不行，语法错误。我又想不出哪里错了。。
帮帮忙吧！
------解决方案--------------------
create table T(Gender char(1), [Section] int)
insert T select 'M ', 1
union all select 'M ', 1
union all select 'F ', 1
union all select 'F ', 2
union all select 'M ', 2
union all select 'M ', 1
union all select 'M ', 2
union all select 'F ', 3
union all select 'M ', 2
union all select 'M ', 3
union all select 'F ', 3
union all select 'F ', 4 --新加的记录
select distinct [Section],
MaleNum=(select count(*) from T where [Section]=tmp.[Section] and Gender= 'M ')
from T as tmp
--result
Section MaleNum
----------- -----------
1 3
2 3
3 1
4 0
(4 row(s) affected)