------------------------------ Commands Entered ------------------------------
WITH
/*******************************
***** Begin of sample data *****
*******************************/
EMP_TABLE(s_no , emp_id , emp_name , emp_salary) AS (
VALUES 
  ( 1 , 123 , 'John'   , 100)
, ( 5 , 123 , 'Sunil'  , 100)
, ( 7 , 123 , 'Raj'    , 500)
, (10 , 123 , 'Joseph' , 101)
)
/*******************************
*****   End of sample data *****
*******************************/
SELECT changed_column
     , CASE changed_column
       WHEN 'Employee Name' THEN
             old_name
       WHEN 'Employee Salary' THEN
             CHAR(old_salary)
       END  AS old_value
     , CASE changed_column
       WHEN 'Employee Name' THEN
             emp_name
       WHEN 'Employee Salary' THEN
             CHAR(emp_salary)
       END  AS new_value
  FROM (SELECT e.*
             , LAG(emp_name  ) OVER(ORDER BY s_no) old_name
             , LAG(emp_salary) OVER(ORDER BY s_no) old_salary
          FROM emp_table e
       ) e
  JOIN (VALUES 'Employee Name' , 'Employee Salary' ) p(changed_column)
   ON  old_name   <> emp_name   AND changed_column = 'Employee Name'
   OR  old_salary <> emp_salary AND changed_column = 'Employee Salary'
 WHERE emp_id = 123
 ORDER BY
       changed_column
     , s_no
;
------------------------------------------------------------------------------

CHANGED_COLUMN  OLD_VALUE   NEW_VALUE  
--------------- ----------- -----------
Employee Name   John        Sunil      
Employee Name   Sunil       Raj        
Employee Name   Raj         Joseph     
Employee Salary 100         500        
Employee Salary 500         101        

  5 record(s) selected.