row_number rank dense_rank

注意工资为3000及2975.00的排序结果

 SQL> select b.dname,
        a.ename,
        a.sal,
        row_number() over(partition by b.dname order by a.sal desc) as rownumber,
        rank() over(partition by b.dname order by a.sal desc) as rank,
        dense_rank() over(partition by b.dname order by a.sal desc) as denserank
   from emp a
  inner join dept b on b.deptno = a.deptno
  order by 1, 3 desc
  /

 DNAME                ENAME           SAL  ROWNUMBER       RANK  DENSERANK
 ---------------------------- -------------------- ---------- ---------- ---------- ----------
 ACCOUNTING           KING           5000          1      1      1
 ACCOUNTING           CLARK          2450          2      2      2
 ACCOUNTING           MILLER         1300          3      3      3
 RESEARCH             FORD           3000          1      1      1
 RESEARCH             SCOTT          3000          2      1      1
 RESEARCH             JONES          2975          3      3      2
 RESEARCH             ADAMS          1100          4      4      3
 RESEARCH             SMITH           800          5      5      4
 SALES                BLAKE          2850          1      1      1
 SALES                ALLEN          1600          2      2      2
 SALES                TURNER         1500          3      3      3
 SALES                WARD           1250          4      4      4
 SALES                MARTIN         1250          5      4      4
 SALES                JAMES           950          6      6      5

 14 rows selected.

 SQL>