请问一条SQL语句，先谢谢了！！！！！！

[Bardo]

原表
A,B,C,
1,1,2
2,1,3
3,1,4
4,2,3
5,2,4
6,3,5
7,3,6

集果记录集：
A,B,C1,C2,C3,C4
1,1,2, 0, 0, 0
2,1,3, 0, 0, 0
3,1,4, 0, 0, 0
4,2,0, 3, 0, 0
5,2,0, 4, 0, 0
6,3,0, 0, 5, 0
7,3,0, 0, 6, 0

[TechnoFantasy]

这个完全用sql语句无法解决，需要自己写一些代码来实现。

[Bardo]

注意B是己知的
是可以实现的，关键我对Case用法不熟！

[warning]

select A,B,(case when b=1 then c else 0 end) c1,
(case when b=2 then c else 0 end) c2,
(case when b=3 then c else 0 end) c3
from tablename

[Yang_]

select A,B,(case b when 1 then c else 0 end) as c1,
(case b when 2 then c else 0 end) as c2,
(case b when 3 then c else 0 end) as c3
from tablename

[Yang_]

select A,B,(case b when 1 then c else 0 end) as c1,
(case b when 2 then c else 0 end) as c2,
(case b when 3 then c else 0 end) as c3,
(case b when 4 then c else 0 end) as c4
from tablename

[Bardo]

楼上的两位高手都对！马上结帐！！！！

[TechnoFantasy]

高手，学了一招。