sql server - How to unpivot set of table records and compare column values? -

i'm selecting top 2 records table ordered date descending. @ moment 2 records returned fine. need transform record data horizontal vertical compare column values. (i.e, column values new rows)

i came across solution of using unpivot in case need join 2 records column name , compare both adding nett difference.

so data being returned no linkage betwen 2 records:

servercounts    proservercount ------------    -------------- 20              6    25              7 

but want present comparison between 2 record's column values :

previousweek   currentweek  nett ------------   -----------  ---- 25             20           5 7              6            1 

question:

how can unpivot 2 table records , compare column values?

now stored procedure looks returning 2 top records:

alter procedure [dbo].[getservercount]       begin           select top 2 [servercounts],[proservercount] [db].[dbo].[servers] order [date] desc  end