请教行列转换SQL
Table1
Number Year Type
6 2001 P001
8 2001 P003
9 2002 P001
1 2004 P005
.. .. ..
需转换为table2
Year P001 P002 P003 ....P013
2001 6 0 0 .... 0
2001 0 0 8 .... 0
2002 9 0 0 .... 0
请教用sql语句如何实现.
[解决办法]
2001 6 0 0 .... 0
2001 0 0 8 .... 0
这里不对吧.
[解决办法]
這個問題的人還真多，給你個參考
Name Subject Result
张三 语文 73
张三 数学 83
张三 物理 93
李四 语文 74
李四 数学 84
李四 物理 94
想变成
姓名 语文 数学 物理
张三 73 83 93
李四 74 84 94
create table #t
(
Name varchar(10) ,
Subject varchar(10) ,
Result int
)
insert into #t(Name , Subject , Result) values( '张三 ', '语文 ', '73 ')
insert into #t(Name , Subject , Result) values( '张三 ', '数学 ', '83 ')
insert into #t(Name , Subject , Result) values( '张三 ', '物理 ', '93 ')
insert into #t(Name , Subject , Result) values( '李四 ', '语文 ', '74 ')
insert into #t(Name , Subject , Result) values( '李四 ', '数学 ', '83 ')
insert into #t(Name , Subject , Result) values( '李四 ', '物理 ', '93 ')
declare @sql varchar(8000)
set @sql = 'select Name as ' + '姓名 '
select @sql = @sql + ' , sum(case Subject when ' ' ' + Subject + ' ' ' then Result end) [ ' + Subject + '] '
from (select distinct Subject from #t) as a
set @sql = @sql + ' from #t group by name '
exec(@sql)
drop table #t
[解决办法]
--如果Type是固定13個
Select
[Year],
SUM(Case Type When 'P001 ' Then Number Else 0 End) As P001,
SUM(Case Type When 'P002 ' Then Number Else 0 End) As P002,
SUM(Case Type When 'P003 ' Then Number Else 0 End) As P003,
...
SUM(Case Type When 'P013 ' Then Number Else 0 End) As P013
From
Table1
Group By
[Year]
[解决办法]
--如果Type不是固定的
Declare @S Varchar(8000)
Select @S = ' Select [Year] '
Select @S = @S + ', SUM(Case Type When ' ' ' + Type + ' ' ' Then Number Else 0 End) As ' + Type
From Table1 Group By Type
Select @S = @S + ' From Table1 Group By [Year] '
EXEC(@S)
[解决办法]
declare @a varchar(1000)
select @a=isnull(@a+ ', ', ' ')+ ' sum(case when Type= ' ' '+Type+ ' ' ' then number else 0 end) [ '+Type+ '] ' from [Table1] group by Type
exec( 'select Year , '+@a+ ' from [Table1] group by Year ')
[解决办法]
--建立测试环境
create table #Tablename(Number int,Year int,Type varchar(10))
insert #Tablename(Number,Year,Type)
select '6 ', '2001 ', 'P001 ' union all
select '8 ', '2001 ', 'P003 ' union all
select '9 ', '2002 ', 'P001 ' union all
select '1 ', '2004 ', 'P005 '
go
--执行测试语句
declare @sql varchar(8000)
set @sql = 'select year '
select @sql = @sql + ',sum(case when type = ' ' '+ type + ' ' ' then number else 0 end) as ' + type
from (select distinct type from #tablename )x
set @sql = @sql + ' from #tablename group by year,type order by year '
exec( @sql)
go
--删除测试环境
drop table #Tablename
go
/*--测试结果
year P001 P003 P005
----------- ----------- ----------- -----------
2001 6 0 0
2001 0 8 0
2002 9 0 0
2004 0 0 1
*/
