行转列

create table test6
(
year number,
month number,
amount number
)
--drop table test6                ---建立表数据


select * from test6 for update


select  year,
max(decode(month,1,amount)) m1,  ---decode
max(decode(month,2,amount)) m2,
max(decode(month,3,amount)) m3,
max(decode(month,4,amount)) m4
 from test6 
 group by  year
 
 with  test61 as 
 (select * from test6
 pivot ( max(amount) for month in 
 (1 as m1,2 as m2,3 as m3,4 as m4))
 )
 select * from  test61
 unpivot ( amount for month in (m1 as 1,m2 as 2,m3 as 3,m4 as 4))2,3 as m3,4 as m4))
 )
 select * from  test61
 unpivot ( amount for month in (m1 as 1,m2 as 2,m3 as 3,m4 as 4))