Oracle dynamic DESC and ASC in order by

Order by is dynamic but the sort order is static.

SELECT ...
Order By CASE WHEN InputParam = 'PRICE' THEN OFFER_开发者_开发技巧PRICE END DESC,
         CASE WHEN InputParam = 'ENDING SOON' THEN EXPIRY_DATE END DESC, 
         CASE WHEN InputParam = 'DISCOUNT' THEN DISC_PERCENTAGE END DESC,
         CASE WHEN InputParam = 'SAVING' THEN SAVING END DESC

Now I need to make sure that the sort order is also dynamic. Is there some way to make sort order dynamic in the above query?

If you also want to make the sort order (ASC/DESC) dynamic, you could do the following:

SELECT ...
Order By CASE WHEN InputParam = 'PRICE' THEN l_so * OFFER_PRICE END,
         CASE WHEN InputParam = 'ENDING SOON' 
              THEN l_so * (SYSDATE - EXPIRY_DATE) END, 
         CASE WHEN InputParam = 'DISCOUNT' THEN l_so * DISC_PERCENTAGE END,
         CASE WHEN InputParam = 'SAVING' THEN l_so * SAVING END

with a variable l_so that contains 1 or -1 depending upon which sort order you want.

This works for me:

order by 
  case when :dir_param = 'ASC' then
    case :col_param 
      when 'col_1_identifier' then col_1_name
      when 'col_2_identifier' then col_2_name
      ...
    end
  end,
  case when :dir_param = 'DSC' then
    case :col_param 
      when 'col_1_identifier' then col_1_name
      when 'col_2_identifier' then col_2_name
      ...
    end
  end desc

or

order by 
case when :dir_param = 'ASC' and :col_param = 'col_1_identifier' then col_1_name end,
case when :dir_param = 'DSC' and :col_param = 'col_1_identifier' then col_1_name end desc,
case when :dir_param = 'ASC' and :col_param = 'col_2_identifier' then col_2_name end,
case when :dir_param = 'DSC' and :col_param = 'col_2_identifier' then col_2_name end desc

replace literals, variable and column names with those specific to your situation. Oracle seemed to be very picky about the placement of the desc sort direction qualifier.