笔记7 case when实现交叉表还有子查询

笔记7 case when实现交叉表还有子查询

case when实现交叉表还有子查询
USE pratice

;with maco as
(
select *,row_number() over (partition by [A] order by (select 1)) as id from testpivot
)

select A ,
  max(case id when '1' then B else null end) A1,
  max(case id when '2' then B else null end) A2,
  max(case id when '3' then B else null end) A3
from maco group by A

select *,row_number() over (partition by [A] order by (select 1)) as id from testpivot

--子查询
--select A
--FROM (
-- SELECT * FROM testpivot
-- )AS [pivottable]