sqlserver下将数据库记录的列记录转换成行记录的方法分享,需要的朋友可以参考下。
假设有张学生成绩表(tb)如下:Name Subject Result
张三 语文 74
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
---------- ----------- ----------- -----------
李四 74 84 94
张三 74 83 93
SQL 语句如下:
代码如下:
create table tb
(
Name varchar(10) ,
Subject varchar(10) ,
Result int
)
insert into tb(Name , Subject , Result) values('张三' , '语文' , 74)
insert into tb(Name , Subject , Result) values('张三' , '数学' , 83)
insert into tb(Name , Subject , Result) values('张三' , '物理' , 93)
insert into tb(Name , Subject , Result) values('李四' , '语文' , 74)
insert into tb(Name , Subject , Result) values('李四' , '数学' , 84)
insert into tb(Name , Subject , Result) values('李四' , '物理' , 94)
go
--静态SQL,指subject只有语文、数学、物理这三门课程。
select name 姓名,
max(case Subject when '语文' then result else 0 end) 语文,
max(case Subject when '数学' then result else 0 end) 数学,
max(case Subject when '物理' then result else 0 end) 物理
from tb
group by name
--动态SQL,指subject不止语文、数学、物理这三门课程。
declare @sql varchar(8000)
set @sql = 'select Name as ' + '姓名'
select @sql = @sql + ' , max(case Subject when ''' + Subject + ''' then Result else 0 end) [' + Subject + ']'
from (select distinct Subject from tb) as a
set @sql = @sql + ' from tb group by name'
exec(@sql)

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