select traderid,materialid,zd1 as price,1 as [month] from traderpric
union all
select traderid,materialid,zd2,2 from traderpric
union all
select traderid,materialid,zd3,3 from traderpric
union all
select traderid,materialid,zd4,4 from traderpric
union all
select traderid,materialid,zd5,5 from traderpric
union all
select traderid,materialid,zd6,6 from traderpric
union all
select traderid,materialid,zd7,7 from traderpric
union all
select traderid,materialid,zd8,8 from traderpric
union all
select traderid,materialid,zd9,9 from traderpric
union all
select traderid,materialid,zd10,10 from traderpric
union all
select traderid,materialid,zd11,11 from traderpric
union all
select traderid,materialid,zd12,12 from traderpric

------解决方案--------------------
SQL code
if object_id('traderprice') is not null drop table traderprice
go
create table traderprice(traderid int,materialid  int,zd1  money,zd2  money,zd3  money,zd4  money,zd5  money,zd6  money,zd7  money,zd8  money,zd9  money,zd10  money,zd11  money,zd12 money)
go
insert into traderprice
select 1 , 3 , 1 ,1.5, 3 , 4 ,4.3,6, 7 ,8 ,9 ,10 ,11 ,12
go
declare @sql varchar(4000),@i int
set @i=1
while @i<=12
begin
    set @sql=isnull(@sql+' union all ','')+'select traderid,materialid,zd'+cast(@i as varchar(2))+' as price,'+cast(@i as varchar(2))+' as [month] from traderprice'
    set @i=@i+1
end
exec(@sql)
/*
traderid    materialid  price                 month
----------- ----------- --------------------- -----------
1           3           1.00                  1
1           3           1.50                  2
1           3           3.00                  3
1           3           4.00                  4
1           3           4.30                  5
1           3           6.00                  6
1           3           7.00                  7
1           3           8.00                  8
1           3           9.00                  9
1           3           10.00                 10
1           3           11.00                 11
1           3           12.00                 12
*/