这个sql谁知道怎么写？

[tedagov328281]

type sj cl
A 2009-01-03 50
A 2009-01-05 50
A 2009-01-07 80
A 2009-01-08 50
A 2009-01-09 10

B 2009-01-03 50
B 2009-01-05 50
B 2009-01-07 80
B 2009-01-08 50
B 2009-01-09 10

想转换为这样的格式,用sql怎么写
时间 A.cl B.cl
2009-01-03 50 50
2009-01-05 50 50
2009-01-07 80 80
2009-01-08 50 50
2009-01-09 10 10

[百年树人]

---测试数据---
if object_id('[tb]') is not null drop table [tb]
go
create table [tb]([type] varchar(1),[sj] datetime,[cl] int)
insert [tb]
select 'A','2009-01-03',50 union all
select 'A','2009-01-05',50 union all
select 'A','2009-01-07',80 union all
select 'A','2009-01-08',50 union all
select 'A','2009-01-09',10 union all
select 'B','2009-01-03',50 union all
select 'B','2009-01-05',50 union all
select 'B','2009-01-07',80 union all
select 'B','2009-01-08',50 union all
select 'B','2009-01-09',10
 
---查询---
select 
  distinct
  sj,
  (select cl from tb where sj=t.sj and [type]='A') as [A.cl],
  (select cl from tb where sj=t.sj and [type]='B') as [B.cl]
from tb  t


---结果---
sj                                                     A.cl        B.cl        
------------------------------------------------------ ----------- ----------- 
2009-01-03 00:00:00.000                                50          50
2009-01-05 00:00:00.000                                50          50
2009-01-07 00:00:00.000                                80          80
2009-01-08 00:00:00.000                                50          50
2009-01-09 00:00:00.000                                10          10

（所影响的行数为 5 行）

[csdyyr]

select a.sj,a.cl,b.cl
from a join b on a.sj=b.sj

[Tomzzu]

LZ就一句话

select sj, sum(case type when 'A' then cl else 0 end) as A_CL,
sum(case type when 'B' then cl else 0 end) as B_CL
from 表名
group by sj
order by sj