行转列
一张表
查询结果为
--行转列
rush:
sql;">
select years,(select amount from Tb_Amount as A where month=1 and A.years=Tb_Amount.years)as m1,(select amount from Tb_Amount as A where month=2 and A.years=Tb_Amount.years)as m2,(select amount from Tb_Amount as A where month=3 and A.years=Tb_Amount.years)as m3
from Tb_Amount group by years
或者为
rush:
sql;">
select years as 年份,sum(case when month='1' then amount end) as 一月,sum(case when month='2' then amount end) as 二月,sum(case when month='3' then amount end) as 三月
from dbo.Tb_Amount group by years order by years desc
2.人员信息表包括姓名 时代 金额
显示行转列
姓名 时代 金额
姓名 年轻 中年 老年
张丽 1000000.00 4000000.00 500000000.00
孙子 2000000.00 12233335.00 4552220010.00
rush:
sql;">
select uname as 姓名,SUM(case when era='年轻' then amount end) as 年轻,SUM(case when era='中年' then amount end) as 中年,SUM(case when era='老年' then amount end) as 老年
from Tb_People group by uname order by uname desc
3.学生表 [Tb_Student]
显示效果
静态sql,指subject只有语文、数学、英语这三门课程。
rush:
sql;">
select sname as 姓名,max(case Subject when '语文' then grade else 0 end) as 语文,max(case Subject when '数学' then grade else 0 end) as 数学,max(case Subject when '英语' then grade else 0 end) as 英语
from dbo.Tb_Student group by sname order by sname desc
--动态sql,指subject不止语文、数学、英语这三门课程。
rush:
sql;">
declare @
sql varchar(8000)
set @
sql = 'select sname as ' + '姓名'
select @
sql = @
sql + ',max(case Subject when ''' + Subject + ''' then grade else 0 end) [' + Subject + ']'
from (select
distinct Subject from Tb_Student) as a
set @
sql = @
sql + ' from Tb_Student group by sname order by sname desc'
exec(@
sql)
oracle中Decode()函数使用 然后将这些累计求和(sum部分）
rush:
sql;">
select t.sname AS 姓名,sum(decode(t.subject,'语文',grade,null))语文,'数学',null)) 数学,'英语',null)) 英语
from Tb_Student t group by sname order by sname desc
列转行
生成
sql代码
生成静态:
rush:
sql;">
select *
from (select sname,[Course ] ='数学',[
score]=[数学] from Tb_students union all
select sname,[Course]='英语',[
score]=[英语] from Tb_students union all
select sname,[Course]='语文',[
score]=[语文] from Tb_students)t
order by sname,case [Course] when '语文' then 1 when '数学' then 2 when '英语' then 3 end
go
--列转行的静态方案：UNPIVOT,
sql2005及以后版本
SELECT sname,Subject,grade
from dbo.Tb_students
unpivot(grade for Subject in([语文],[数学],[英语]))as up
GO
--列转行的动态方案：UNPIVOT,sql2005及以后版本
--因为行是动态所以这里就从informatION_SCHEMA.COLUMNS视图中获取列来构造行，同样也使用了XML处理。
declare @s nvarchar(4000)
select @s=isnull(@s+',','')+quotename(Name)
from syscolumns where ID=object_id('Tb_students') and Name not in('sname')
order by Colid
exec('select sname,[Subject],[grade] from Tb_students unpivot ([grade] for [Subject] in('+@s+'))b')
go
select
sname,[grade]
from
Tb_students
unpivot
([grade] for [Subject] in([数学],[英语],[语文]))b
