Rate Comparison query

Question

Table Structure
Po_no number(12)
Item_code varchar210),
rate number(12,3)I want to output like that
Item_code         Current Rate            Previous RateWhere current rate = rate of Max(po_no) and Previous Rate = rate of 2nd Max(po_no)

Answer 1

Maybe NOT TESTED!
select item_code "Item_code",max(max_rate) "Current Rate",min(max_rate) "Previous Rate"
  from (select item_code,max(rate) max_rate
          from (select po_no,item_code,rate,
                       dense_rank() over (partition by po_no order by rate desc) r
                  from your_table
         where r in (1,2)
         group by item_code,r
group by item_codeRegards
Etbin
Edited by: Etbin on 21.2.2011 17:33
returns null Previous Rate when having one value only
select item_code "Item_code",max(max_rate) "Current Rate",min(case r when 2 then max_rate end) "Previous Rate"
  from (select item_code,max(rate) max_rate,r
          from (select po_no,item_code,rate,
                       dense_rank() over (partition by item_code order by rate desc) r
                  from (select 10 po_no,'1' item_code,12.345 rate from dual union all
                        select 10,'1',12.678 from dual union all
                        select 10,'1',12.234 from dual union all
                        select 10,'1',12.789 from dual union all
                        select 10,'2',10.678 from dual union all
                        select 10,'2',10.234 from dual union all
                        select 10,'2',10.789 from dual union all
                        select 10,'3',10.001 from dual
         where r in (1,2)
         group by item_code,r
group by item_codeEdited by: Etbin on 21.2.2011 17:39