ROW_NUMBER

ROW_NUMBER function deals with the row numbering for ranking. Its general format:

ROW_NUMBER over (analytical clause)

analytical clause could be

  • ordering
  • partitioning
  • windowing
  • or the combination of above three

CREATE TABLE EMP (EMPNO NUMBER(4) NOT NULL,
                  ENAME VARCHAR2(10),
                  JOB VARCHAR2(9),
                  SAL NUMBER(7, 2),
                  DEPTNO NUMBER(2));

INSERT INTO EMP VALUES (1, 'SMITH', 'CLERK',     800,    20);
INSERT INTO EMP VALUES (2, 'ALLEN', 'SALESMAN', 1600,    30);
INSERT INTO EMP VALUES (3, 'WARD',  'SALESMAN', 1250,    30);
INSERT INTO EMP VALUES (4, 'JONES', 'MANAGER',  2975,    20);
INSERT INTO EMP VALUES (5, 'MARTIN','SALESMAN', 1250,    30);
INSERT INTO EMP VALUES (6, 'BLAKE', 'MANAGER',  2850,    30);
INSERT INTO EMP VALUES (7, 'CLARK', 'MANAGER',  2850,    10);
INSERT INTO EMP VALUES (8, 'SCOTT', 'ANALYST',  3000,    20);
INSERT INTO EMP VALUES (9, 'KING',  'PRESIDENT',3000,    10);
INSERT INTO EMP VALUES (10,'TURNER','SALESMAN', 1500,    30);
INSERT INTO EMP VALUES (11,'ADAMS', 'CLERK',    1500,    20);

SQL> select ename, sal, row_number() over (order by sal) toprank from emp;

ENAME             SAL    TOPRANK
---------- ---------- ----------
SMITH             800          1
WARD             1250          2
MARTIN           1250          3
TURNER           1500          4
ADAMS            1500          5
ALLEN            1600          6
CLARK            2850          7
BLAKE            2850          8
JONES            2975          9
KING             3000         10
SCOTT            3000         11

11 rows selected.

SQL>

It is better to add the order by clause to the sql itself since different ordering may be used for different analytical functions.


SQL> select ename, sal, row_number() over (order by sal) toprank
  2  from emp
  3  order by sal;

ENAME             SAL    TOPRANK
---------- ---------- ----------
SMITH             800          1
WARD             1250          2
MARTIN           1250          3
TURNER           1500          4
ADAMS            1500          5
ALLEN            1600          6
CLARK            2850          7
BLAKE            2850          8
JONES            2975          9
KING             3000         10
SCOTT            3000         11

11 rows selected.

SQL>

We can also do the reverse ordering:


SQL> select ename, sal, row_number() over (order by sal desc) toprank
  2  from emp
  3  order by sal desc;

ENAME             SAL    TOPRANK
---------- ---------- ----------
KING             3000          1
SCOTT            3000          2
JONES            2975          3
BLAKE            2850          4
CLARK            2850          5
ALLEN            1600          6
ADAMS            1500          7
TURNER           1500          8
MARTIN           1250          9
WARD             1250         10
SMITH             800         11

11 rows selected.

SQL>

We can also reorder on some column other than the column used in row_number function.


SQL> select ename, sal, row_number() over (order by sal desc) toprank
  2  from emp
  3  order by sal, JOB;

ENAME             SAL    TOPRANK
---------- ---------- ----------
SMITH             800         11
WARD             1250         10
MARTIN           1250          9
ADAMS            1500          7
TURNER           1500          8
ALLEN            1600          6
BLAKE            2850          4
CLARK            2850          5
JONES            2975          3
SCOTT            3000          2
KING             3000          1

11 rows selected.

SQL>
Home »
Oracle »
Analytical Functions » 

ROW_NUMBER:
  1. ROW_NUMBER
  2. Get top n rows with row_number
  3. NULL and row_number
  4. Place NULLS FIRST in ROW_NUMBER
  5. Place NULLS LAST in ROW_NUMBER
  6. Using the ROW_NUMBER with group by
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