行转列
一张表
查询结果为
--行转列
|
1
2
3
4
|
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 m3from Tb_Amount group by years |
或者为
|
1
2
3
4
5
|
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
|
1
2
3
4
5
|
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。
|
1
2
3
4
5
|
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。
|
1
2
3
4
5
6
|
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 aset @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）
|
1
2
3
4
5
|
select t.sname AS 姓名,sum(decode(t.subject,'语文',grade,null))语文 ,sum(decode(t.subject,'数学',grade,null)) 数学,sum(decode(t.subject,'英语',grade,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:
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
|
select *from (select sname,[Course ] ='数学',[Score]=[数学] from Tb_students union allselect sname,[Course]='英语',[Score]=[英语] from Tb_students union allselect sname,[Course]='语文',[Score]=[语文] from Tb_students)torder by sname,case [Course] when '语文' then 1 when '数学' then 2 when '英语' then 3 endgo --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 Colidexec('select sname,[Subject],[grade] from Tb_students unpivot ([grade] for [Subject] in('+@s+'))b')goselect sname,[Subject],[grade]from Tb_studentsunpivot ([grade] for [Subject] in([数学],[英语],[语文]))b |
