sqlserver行转列

一丶行专列案例【借鉴】

1.建立表格

IF OBJECT_ID('tb') IS NOT NULL DROP TABLE tb

go

CREATE TABLE tb(姓名 VARCHAR(10),课程 VARCHAR(10),分数 INT)

insert into tb VALUES ('张三','语文',74)
insert into tb VALUES ('张三','数学',83)
insert into tb VALUES ('张三','物理',93)
insert into tb VALUES ('李四','语文',74)
insert into tb VALUES ('李四','数学',84)
insert into tb VALUES ('李四','物理',94)

go

SELECT * FROM tb

go

动态sql

--使用stuff()

DECLARE @sql VARCHAR(8000)

SET @sql=''  --初始化变量 @sql

SELECT @sql= @sql+',' + 课程 FROM tb GROUP BY 课程 --变量多值赋值

SET @sql= STUFF(@sql,1,1,'')--去掉首个','

SET @sql='select * from tb pivot (max(分数) for 课程 in ('+@sql+'))a'

PRINT @sql

exec(@sql)

--或使用isnull()

DECLARE @sql VARCHAR(8000)

--获得课程集合

SELECT @sql= ISNULL(@sql+',','')+课程 FROM tb
GROUP BY 课程           

SET @sql='select * from tb pivot (max(分数) for 课程 in ('+@sql+'))a'

exec(@sql)

二丶实战

行转列

 

DECLARE @sql VARCHAR(8000)
SET @sql=''  --初始化变量 @sql
SELECT @sql= @sql+',' + '['+Admission_Grade+']' FROM #temp WHERE Admission_Grade>YEAR(GETDATE())-3 GROUP BY Admission_Grade ORDER BY Admission_Grade DESC--变量多值赋值
SET @sql= STUFF(@sql,1,1,'')--去掉首个','

SET @sql='select * from #temp pivot (max(studentCount) for Admission_Grade in ('+@sql+'))a'
PRINT @sql
exec(@sql)

2.

DECLARE @sql VARCHAR(8000)
SET @sql=''  --初始化变量 @sql
SELECT @sql= @sql+',' + '['+Admission_Grade+']' FROM #temp WHERE Admission_Grade>YEAR(GETDATE())-3 GROUP BY Admission_Grade ORDER BY Admission_Grade DESC--变量多值赋值
SET @sql= STUFF(@sql,1,1,'')--去掉首个','
SET @sql = ' select m.* , n.stuCount from
(select  * from (select * from #temp) a pivot (max(studentCount) for Admission_Grade in (' + @sql
    + ')) b) m,
(select Magor_Code,StudyMode,StudyHierarchy,sum(studentCount) as stuCount from #temp WHERE  Admission_Grade>YEAR(GETDATE())-3  group by Magor_Code,StudyMode,StudyHierarchy) n
where m.Magor_Code= n.Magor_Code AND m.StudyMode=n.StudyMode AND m.StudyHierarchy=n.StudyHierarchy
'
PRINT @sql
exec(@sql)

 

转载于:https://www.cnblogs.com/chenze-Index/p/10454742.html