1. Raw data (partial)
SELECT * FROM SCOTT.EMP ;
2. Use the Row_number() over() function to sort
SELECT EMPNO,ENAME,SAL,DEPTNO,Row_number() over( order by sal) rs FROM SCOTT.EMP ;
Sort by salary and add sequence number
3. Use the Row_number() over() function to group and sort
SELECT EMPNO,ENAME,SAL,DEPTNO,Row_number() over(partition by DEPTNO order by sal) rs FROM SCOTT.EMP;