Identify the Changes in Columns Data

Try the below script,

--------------------------------- DEFINITION
DECLARE @temp TABLE (SALESID int,UPDATEDATE datetime, COL1 int,COL2 int,COL3 int,COL4 int)
INSERT INTO @temp VALUES(1,getdate()-1,null,64,null,null)
INSERT INTO @temp VALUES(1,getdate(),null,null,null,32)
INSERT INTO @temp VALUES(2,getdate()-1,22,null,null,null)
INSERT INTO @temp VALUES(2,getdate(),null,44,null,55)
---------------------------------- QUERY
-- BEGIN CTE
;WITH CTE AS (
SELECT SALESID,COLS FROM (
        SELECT SALESID, COL1 ,COL2 ,COL3 ,COL4  from (
                SELECT *,dense_rank() over (order by updatedate) as [Dense] FROM @temp 
        ) X
        WHERE [Dense] <=2
) p
unpivot
(
        COLVALUES FOR COLS in (COL1,COL2,COL3,COL4)
) as upvt
) -- END OF CTE
SELECT SALESID, 
       Stuff((SELECT ',' + COLS 
              FROM   CTE 
              WHERE  SALESID = a.SALESID 
              FOR xml path('')), 1, 1, '') COLS
FROM   CTE a 
GROUP  BY  SALESID

---

Regards, RSingh