http://topic.csdn.net/u/20080614/17/22e73f33-f071-46dc-b9bf-321204b1656f.html
解决方案 »
- 怎样在group中使用having
- Delete与Truncate Table
- 关于重新编译存储过程的问题
- 求一SQL语句,急!
- sql server 2008 peer-to-peer 复制,怎么样定时执行
- 怎么用游标查询从N到M的记录?
- 变量声明的一个问题
- SQL2008内存占用过大,有没有什么办法?
- 有向图AOE网关键路径用SQL存储过程实现!!前辈们帮帮小弟啦,谢谢
- 请教:如何得到sqlserver服务器的当前连接数?
- 服务器: 消息 306,级别 16,状态 2,过程 viewname,行 3 不能比较或排序 text、ntext 和 image 数据类型,除非使用 IS NULL 或 LIKE 运算符。
- sql字符合并问题
MAX(CASE WHEN subject ='语文' THEN SCORE END)AS 语文,
MAX(CASE WHEN subject =' 数学'THEN SCORE END)AS 数学
FROM
(SELECT stu_name,subject FROM student T JOIN score T1 WHERE T.stu_id=T1.stu_id)AS T
GROUP BY stu_name
/******************************************************************************************************************************************************
以学生成绩为例子,比较形象易懂整理人:中国风(Roy)日期:2008.06.06
******************************************************************************************************************************************************/--1、行互列
--> --> (Roy)生成測試數據if not object_id('Class') is null
drop table Class
Go
Create table Class([Student] nvarchar(2),[Course] nvarchar(2),[Score] int)
Insert Class
select N'张三',N'语文',78 union all
select N'张三',N'数学',87 union all
select N'张三',N'英语',82 union all
select N'张三',N'物理',90 union all
select N'李四',N'语文',65 union all
select N'李四',N'数学',77 union all
select N'李四',N'英语',65 union all
select N'李四',N'物理',85
Go
--2000方法:
动态:declare @s nvarchar(4000)
set @s=''
Select @s=@s+','+quotename([Course])+'=max(case when [Course]='+quotename([Course],'''')+' then [Score] else 0 end)'
from Class group by[Course]
exec('select [Student]'+@s+' from Class group by [Student]')
生成静态:select
[Student],
[数学]=max(case when [Course]='数学' then [Score] else 0 end),
[物理]=max(case when [Course]='物理' then [Score] else 0 end),
[英语]=max(case when [Course]='英语' then [Score] else 0 end),
[语文]=max(case when [Course]='语文' then [Score] else 0 end)
from
Class
group by [Student]GO
动态:declare @s nvarchar(4000)
Select @s=isnull(@s+',','')+quotename([Course]) from Class group by[Course]
exec('select * from Class pivot (max([Score]) for [Course] in('+@s+'))b')生成静态:
select *
from
Class
pivot
(max([Score]) for [Course] in([数学],[物理],[英语],[语文]))b生成格式:
/*
Student 数学 物理 英语 语文
------- ----------- ----------- ----------- -----------
李四 77 85 65 65
张三 87 90 82 78(2 行受影响)
*/------------------------------------------------------------------------------------------
go
--加上总成绩(学科平均分)--2000方法:
动态:declare @s nvarchar(4000)
set @s=''
Select @s=@s+','+quotename([Course])+'=max(case when [Course]='+quotename([Course],'''')+' then [Score] else 0 end)'
from Class group by[Course]
exec('select [Student]'+@s+',[总成绩]=sum([Score]) from Class group by [Student]')--加多一列(学科平均分用avg([Score]))生成动态:select
[Student],
[数学]=max(case when [Course]='数学' then [Score] else 0 end),
[物理]=max(case when [Course]='物理' then [Score] else 0 end),
[英语]=max(case when [Course]='英语' then [Score] else 0 end),
[语文]=max(case when [Course]='语文' then [Score] else 0 end),
[总成绩]=sum([Score]) --加多一列(学科平均分用avg([Score]))
from
Class
group by [Student]go--2005方法:动态:declare @s nvarchar(4000)
Select @s=isnull(@s+',','')+quotename([Course]) from Class group by[Course] --isnull(@s+',','') 去掉字符串@s中第一个逗号
exec('select [Student],'+@s+',[总成绩] from (select *,[总成绩]=sum([Score])over(partition by [Student]) from Class) a
pivot (max([Score]) for [Course] in('+@s+'))b ')生成静态:select
[Student],[数学],[物理],[英语],[语文],[总成绩]
from
(select *,[总成绩]=sum([Score])over(partition by [Student]) from Class) a --平均分时用avg([Score])
pivot
(max([Score]) for [Course] in([数学],[物理],[英语],[语文]))b 生成格式:/*
Student 数学 物理 英语 语文 总成绩
------- ----------- ----------- ----------- ----------- -----------
李四 77 85 65 65 292
张三 87 90 82 78 337(2 行受影响)
*/go--2、列转行
--> --> (Roy)生成測試數據if not object_id('Class') is null
drop table Class
Go
Create table Class([Student] nvarchar(2),[数学] int,[物理] int,[英语] int,[语文] int)
Insert Class
select N'李四',77,85,65,65 union all
select N'张三',87,90,82,78
Go--2000:动态:declare @s nvarchar(4000)
select @s=isnull(@s+' union all ','')+'select [Student],[Course]='+quotename(Name,'''')--isnull(@s+' union all ','') 去掉字符串@s中第一个union all
+',[Score]='+quotename(Name)+' from Class'
from syscolumns where ID=object_id('Class') and Name not in('Student')--排除不转换的列
order by Colid
exec('select * from ('+@s+')t order by [Student],[Course]')--增加一个排序生成静态:
select *
from (select [Student],[Course]='数学',[Score]=[数学] from Class union all
select [Student],[Course]='物理',[Score]=[物理] from Class union all
select [Student],[Course]='英语',[Score]=[英语] from Class union all
select [Student],[Course]='语文',[Score]=[语文] from Class)t
order by [Student],[Course]go
--2005:动态:declare @s nvarchar(4000)
select @s=isnull(@s+',','')+quotename(Name)
from syscolumns where ID=object_id('Class') and Name not in('Student')
order by Colid
exec('select Student,[Course],[Score] from Class unpivot ([Score] for [Course] in('+@s+'))b')go
select
Student,[Course],[Score]
from
Class
unpivot
([Score] for [Course] in([数学],[物理],[英语],[语文]))b生成格式:
/*
Student Course Score
------- ------- -----------
李四 数学 77
李四 物理 85
李四 英语 65
李四 语文 65
张三 数学 87
张三 物理 90
张三 英语 82
张三 语文 78(8 行受影响)
*/
SELECT stu_name,
MAX(CASE WHEN subject ='语文' THEN SCORE END)AS 语文,
MAX(CASE WHEN subject =' 数学'THEN SCORE END)AS 数学
FROM
(SELECT stu_name,subject FROM student T JOIN score T1 WHERE T.stu_id=T1.stu_id)AS T
GROUP BY stu_name
if object_id('student') is not null
drop table student
gocreate table student (stu_id int,stu_name varchar(10))
insert into student select
1,'张三' union all select
2,'李四'
if object_id('score') is not null
drop table score
go
create table score(s_id int,stu_id int,subject varchar(10),score int)
insert into score select
1,1,'语文',90 union all select
2,1,'数学',80 union all select
3,2,'语文',60 union all select
4,2,'数学',70
declare @s nvarchar(4000)
set @s=''
Select @s=@s+','+quotename([subject])+'=max(case when [subject]='+quotename([subject],'''')+' then [Score] else 0 end)'
from score s group by [subject]
exec('select [stu_name]'+@s+' from score s join student on s.stu_id=student.stu_id group by [stu_name]')
/*
stu_name 数学 语文
---------- ----------- -----------
李四 70 60
张三 80 90*/