sql数据统计的问题

[rodking]

现有两个关联表，CustomerID为关联列
表1结构：
CustomerID，CompanyId,.....
12 YA
13 YA
14 YA
15 YC
16 YD

表2结构：
CustomerID,Disabled
12 0 (未启用)
14 1
15 1

现要统计分公司（CompanyId）启用的客户的数量，分公司客户总数，启用客户所占比例，用分公司分组。
结果类似：
启用数量 总数 所占比例 分公司
2 3 66.67% YA
1 1 100% YC



请问这样的sql语句该怎么写？对于高手来说，应该很简单的,多谢

[中国风]

select
	cast(Disabled as int) as 启用数量,--bit时要转换
	count(1) as  总数,
	ltrim(str(cast(Disabled as decimal(18,5))/count(1),18,2))+'%'		as 所占比例,
	b.CompanyId as 分公司 
from 
	t1 a
join
	t2 b on a.CustomerID=b.CustomerID
group by b.CompanyId

[pt1314917]

declare @t1 table(customerid int,companyid varchar(10))
insert into @t1 select 12,'YA'
insert into @t1 select 13,'YA'
insert into @t1 select 14,'YA'
insert into @t1 select 15,'YC'
insert into @t1 select 16,'YD'

declare @t2 table(companyid int,Disabled  int)
insert into @t2 select 12,0
insert into @t2 select 14,1
insert into @t2 select 15,1

select 
起用数量=sum(case Disabled when 1 then 1 else 0 end),
总数=count(1),
所占比例=ltrim(cast(sum(case Disabled when 1 then 1 else 0 end)*100.00/count(1) as numeric(5,2)))+'%',
分公司=a.companyid
from @t1 a,@t2 b
where a.customerid=b.companyid
group by a.companyid