SQLServer处理行转列和列转行

掌握SQL Server 行转列和列转行

1、列转行

      数据经过计算加工后会直接生成前端图表需要的数据源，但是程序里又需要把该数据经过列转行写入中间表中，下次再查询该数据时直接从中间表查询数据。

1.1 列换行语法

table_source

UNPIVOT(

value_column

FOR pivot_column

IN(<column_list>)

)

1.2  行转列案例

WITH T
AS
(
    SELECT 1 as TeamId,'测试团队1' as Team,80 'MEN',20 'WOMEN'
    UNION 
    SELECT 2 as TeamId,'测试团队2' as Team,30 'MEN',70 'WOMEN' 
)

---列转行------------------------------------
SELECT TeamId,Team ,TYPE=ATTRIBUTE,CNT=VALUE
FROM T 
UNPIVOT (
  VALUE FOR ATTRIBUTE IN ([MEN],[WOMEN])
) AS UPV

2、 行转列

       行转列主要是从中间表里查询数据，SQL SERVER2005以下的版本则可以使用聚合函数来完成。

2.1 行转列语法

table_source

PIVOT(

聚合函数（value_column）

FOR pivot_column

IN(<column_list>)

)

2.2、使用PIVOT实现

WITH T
AS
(
  SELECT  1 AS ID,'测试团队1' TEAM,'MEN' ITEM,80 CENT
  UNION
  SELECT  1 AS ID,'测试团队1' TEAM,'WOMEN' ITEM,20 CENT
  UNION
  SELECT  2 AS ID,'测试团队2' TEAM,'MEN' ITEM,30 CENT
  UNION
  SELECT  2 AS ID,'测试团队2' TEAM,'WOMEN' ITEM,70 CENT
)

SELECT * FROM T PIVOT (SUM(CENT) FOR ITEM IN ([MEN],[WOMEN])) A

2.3、使用聚合函数实现

WITH T
AS
(
  SELECT  1 AS ID,'测试团队1' TEAM,'MEN' ITEM,80 CENT
  UNION
  SELECT  1 AS ID,'测试团队1' TEAM,'WOMEN' ITEM,20 CENT
  UNION
  SELECT  2 AS ID,'测试团队2' TEAM,'MEN' ITEM,30 CENT
  UNION
  SELECT  2 AS ID,'测试团队2' TEAM,'WOMEN' ITEM,70 CENT
)

SELECT ID,TEAM,
SUM(CASE WHEN ITEM='MEN' THEN CENT ELSE 0 END) 'MEN',
SUM(CASE WHEN ITEM='WOMEN' THEN CENT ELSE 0 END) 'WOMEN' 
FROM T
GROUP BY ID,TEAM

参考资料

http://www.cnblogs.com/zhangzt/archive/2010/07/29/1787825.html

http://www.cnblogs.com/aspnethot/articles/1762665.html