文档介绍：sql数据库面试题及答案
sql数据库面试题及答案
=txt>，关于group by
表内容：
2005-05-09 胜
2005-05-09
sql数据库面试题及答案
sql数据库面试题及答案
=txt>，关于group by
表内容：
2005-05-09 胜
2005-05-09 胜
2005-05-09 负
2005-05-09 负
2005-05-10 胜
2005-05-10 负
2005-05-10 负
如果要生成下列结果, 该如何写sql语句?
胜负
2005-05-09 2 2
2005-05-10 1 2
------------------------------------------
create table #tmp(rq varchar(10),shengfu nchar(1))
insert into #tmp values(2005-05-09,胜)
insert into #tmp values(2005-05-09,胜)
insert into #tmp values(2005-05-09,负)
insert into #tmp values(2005-05-09,负)
insert into #tmp values(2005-05-10,胜)
insert into #tmp values(2005-05-10,负)
insert into #tmp values(2005-05-10,负)
1)select rq, sum(case when shengfu=胜 then 1 else 0 end)胜,sum(case when shengfu=负 then 1 else 0 end)负 from #tmp group by rq
2) select ,, from (
select rq,勝=count(*) from #tmp where shengfu=胜group by rq)n inner join
(select rq,負=count(*) from #tmp where shengfu=负group by rq)m on =
3)select , 胜, 负 from
(select col001,count(col001) a1 from temp1 where col002=胜group