Oracle PL/SQL/Analytical Functions/DENSE RANK

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Compare rank() and dense_rank()

   <source lang="sql">
 

SQL> CREATE TABLE EMP (EMPNO NUMBER(4) NOT NULL,

 2                    ENAME VARCHAR2(10),
 3                    JOB VARCHAR2(9),
 4                    MGR NUMBER(4),
 5                    HIREDATE DATE,
 6                    SAL NUMBER(7, 2),
 7                    COMM NUMBER(7, 2),
 8                    DEPTNO NUMBER(2));

Table created. SQL> SQL> INSERT INTO EMP VALUES (7369, "SMITH", "CLERK", 7902, TO_DATE("17-DEC-1980", "DD-MON-YYYY"), 800, NULL, 20); 1 row created. SQL> INSERT INTO EMP VALUES (7499, "ALLEN", "SALESMAN", 7698, TO_DATE("20-FEB-1981", "DD-MON-YYYY"), 1600, 300, 30); 1 row created. SQL> INSERT INTO EMP VALUES (7521, "WARD", "SALESMAN", 7698, TO_DATE("22-FEB-1981", "DD-MON-YYYY"), 1250, 500, 30); 1 row created. SQL> INSERT INTO EMP VALUES (7566, "JONES", "MANAGER", 7839, TO_DATE("2-APR-1981", "DD-MON-YYYY"), 2975, NULL, 20); 1 row created. SQL> INSERT INTO EMP VALUES (7654, "MARTIN", "SALESMAN", 7698,TO_DATE("28-SEP-1981", "DD-MON-YYYY"), 1250, 1400, 30); 1 row created. SQL> INSERT INTO EMP VALUES (7698, "BLAKE", "MANAGER", 7839,TO_DATE("1-MAY-1981", "DD-MON-YYYY"), 2850, NULL, 30); 1 row created. SQL> INSERT INTO EMP VALUES (7782, "CLARK", "MANAGER", 7839,TO_DATE("9-JUN-1981", "DD-MON-YYYY"), 2450, NULL, 10); 1 row created. SQL> INSERT INTO EMP VALUES (7788, "SCOTT", "ANALYST", 7566,TO_DATE("09-DEC-1982", "DD-MON-YYYY"), 3000, NULL, 20); 1 row created. SQL> INSERT INTO EMP VALUES (7839, "KING", "PRESIDENT", NULL,TO_DATE("17-NOV-1981", "DD-MON-YYYY"), 5000, NULL, 10); 1 row created. SQL> INSERT INTO EMP VALUES (7844, "TURNER", "SALESMAN", 7698,TO_DATE("8-SEP-1981", "DD-MON-YYYY"), 1500, 0, 30); 1 row created. SQL> INSERT INTO EMP VALUES (7876, "ADAMS", "CLERK", 7788,TO_DATE("12-JAN-1983", "DD-MON-YYYY"), 1100, NULL, 20); 1 row created. SQL> INSERT INTO EMP VALUES (7900, "JAMES", "CLERK", 7698,TO_DATE("3-DEC-1981", "DD-MON-YYYY"), 950, NULL, 30); 1 row created. SQL> INSERT INTO EMP VALUES (7902, "FORD", "ANALYST", 7566,TO_DATE("3-DEC-1981", "DD-MON-YYYY"), 3000, NULL, 20); 1 row created. SQL> INSERT INTO EMP VALUES (7934, "MILLER", "CLERK", 7782,TO_DATE("23-JAN-1982", "DD-MON-YYYY"), 1300, NULL, 10); 1 row created. SQL> SQL> CREATE TABLE DEPT (DEPTNO NUMBER(2),DNAME VARCHAR2(14),LOC VARCHAR2(13) ); Table created. SQL> SQL> INSERT INTO DEPT VALUES (10, "ACCOUNTING", "NEW YORK"); 1 row created. SQL> INSERT INTO DEPT VALUES (20, "RESEARCH", "DALLAS"); 1 row created. SQL> INSERT INTO DEPT VALUES (30, "SALES", "CHICAGO"); 1 row created. SQL> INSERT INTO DEPT VALUES (40, "OPERATIONS", "BOSTON"); 1 row created. SQL> SQL> select rank() over ( order by hiredate ) "RANK",

 2  dense_rank() over ( order by hiredate ) "DENSE_RANK",
 3  ename,hiredate
 4  from emp order by hiredate;
     RANK DENSE_RANK ENAME      HIREDATE

---------- ---------- ---------
        1          1 SMITH      17-DEC-80
        2          2 ALLEN      20-FEB-81
        3          3 WARD       22-FEB-81
        4          4 JONES      02-APR-81
        5          5 BLAKE      01-MAY-81
        6          6 CLARK      09-JUN-81
        7          7 TURNER     08-SEP-81
        8          8 MARTIN     28-SEP-81
        9          9 KING       17-NOV-81
       10         10 JAMES      03-DEC-81
       10         10 FORD       03-DEC-81
     RANK DENSE_RANK ENAME      HIREDATE

---------- ---------- ---------
       12         11 MILLER     23-JAN-82
       13         12 SCOTT      09-DEC-82
       14         13 ADAMS      12-JAN-83

14 rows selected. SQL> SQL> drop table emp cascade constraints; Table dropped. SQL> drop table dept cascade constraints; Table dropped.

 </source>
   
  


Deal with Null in dense_rank

   <source lang="sql">

SQL> CREATE TABLE all_sales (

 2    year INTEGER,
 3    month INTEGER,
 4    prd_type_id INTEGER,
 5    emp_id INTEGER ,
 6    amount NUMBER(8, 2)
 7  );

Table created. SQL> SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,1    ,1          ,21    ,16034.84);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,2    ,1          ,21    ,15644.65);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,3    ,2          ,21    ,20167.83);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,4    ,2          ,21    ,25056.45);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,5    ,2          ,21    ,NULL);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,6    ,1          ,21    ,15564.66);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,7    ,1          ,21    ,15644.65);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,8    ,1          ,21    ,16434.82);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,9    ,1          ,21    ,19654.57);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,10   ,1          ,21    ,21764.19);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,11   ,1          ,21    ,13026.73);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,12   ,2          ,21    ,10034.64);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,1    ,2          ,22    ,16634.84);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,1    ,2          ,21    ,26034.84);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,2    ,1          ,21    ,12644.65);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,3    ,1          ,21    ,NULL);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,4    ,1          ,21    ,25026.45);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,5    ,1          ,21    ,17212.66);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,6    ,1          ,21    ,15564.26);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,7    ,2          ,21    ,62654.82);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,8    ,2          ,21    ,26434.82);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,9    ,2          ,21    ,NULL);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,10   ,2          ,21    ,NULL);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,11   ,1          ,21    ,NULL);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,12   ,1          ,21    ,NULL);

1 row created. SQL> SQL> select * from all_sales;

     YEAR      MONTH PRD_TYPE_ID     EMP_ID     AMOUNT

---------- ----------- ---------- ----------
     2006          1           1         21   16034.84
     2006          2           1         21   15644.65
     2006          3           2         21   20167.83
     2006          4           2         21   25056.45
     2006          5           2         21
     2006          6           1         21   15564.66
     2006          7           1         21   15644.65
     2006          8           1         21   16434.82
     2006          9           1         21   19654.57
     2006         10           1         21   21764.19
     2006         11           1         21   13026.73
     2006         12           2         21   10034.64
     2005          1           2         22   16634.84
     2005          1           2         21   26034.84
     2005          2           1         21   12644.65
     2005          3           1         21
     2005          4           1         21   25026.45
     2005          5           1         21   17212.66
     2005          6           1         21   15564.26
     2005          7           2         21   62654.82
     2005          8           2         21   26434.82
     2005          9           2         21
     2005         10           2         21
     2005         11           1         21
     2005         12           1         21

25 rows selected. SQL> SQL> --Deal with Null in dense_rank SQL> SQL> SELECT

 2   prd_type_id, SUM(amount),
 3   RANK() OVER (ORDER BY SUM(amount) DESC) AS rank,
 4   DENSE_RANK() OVER (ORDER BY SUM(amount) DESC) AS dense_rank
 5  FROM all_sales
 6  GROUP BY prd_type_id
 7  ORDER BY prd_type_id;

PRD_TYPE_ID SUM(AMOUNT) RANK DENSE_RANK


----------- ---------- ----------
         1   204217.13          1          1
         2   187018.24          2          2

SQL> SQL> SQL> drop table all_sales; Table dropped. SQL> SQL>


 </source>
   
  


Deal with Null in Rank

   <source lang="sql">

SQL> CREATE TABLE all_sales (

 2    year INTEGER,
 3    month INTEGER,
 4    prd_type_id INTEGER,
 5    emp_id INTEGER ,
 6    amount NUMBER(8, 2)
 7  );

Table created. SQL> SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,1    ,1          ,21    ,16034.84);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,2    ,1          ,21    ,15644.65);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,3    ,2          ,21    ,20167.83);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,4    ,2          ,21    ,25056.45);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,5    ,2          ,21    ,NULL);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,6    ,1          ,21    ,15564.66);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,7    ,1          ,21    ,15644.65);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,8    ,1          ,21    ,16434.82);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,9    ,1          ,21    ,19654.57);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,10   ,1          ,21    ,21764.19);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,11   ,1          ,21    ,13026.73);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,12   ,2          ,21    ,10034.64);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,1    ,2          ,22    ,16634.84);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,1    ,2          ,21    ,26034.84);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,2    ,1          ,21    ,12644.65);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,3    ,1          ,21    ,NULL);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,4    ,1          ,21    ,25026.45);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,5    ,1          ,21    ,17212.66);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,6    ,1          ,21    ,15564.26);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,7    ,2          ,21    ,62654.82);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,8    ,2          ,21    ,26434.82);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,9    ,2          ,21    ,15644.65);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,10   ,2          ,21    ,NULL);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,11   ,1          ,21    ,NULL);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,12   ,1          ,21    ,NULL);

1 row created. SQL> SQL> select * from all_sales;

     YEAR      MONTH PRD_TYPE_ID     EMP_ID     AMOUNT

---------- ----------- ---------- ----------
     2006          1           1         21   16034.84
     2006          2           1         21   15644.65
     2006          3           2         21   20167.83
     2006          4           2         21   25056.45
     2006          5           2         21
     2006          6           1         21   15564.66
     2006          7           1         21   15644.65
     2006          8           1         21   16434.82
     2006          9           1         21   19654.57
     2006         10           1         21   21764.19
     2006         11           1         21   13026.73
     2006         12           2         21   10034.64
     2005          1           2         22   16634.84
     2005          1           2         21   26034.84
     2005          2           1         21   12644.65
     2005          3           1         21
     2005          4           1         21   25026.45
     2005          5           1         21   17212.66
     2005          6           1         21   15564.26
     2005          7           2         21   62654.82
     2005          8           2         21   26434.82
     2005          9           2         21   15644.65
     2005         10           2         21
     2005         11           1         21
     2005         12           1         21

25 rows selected. SQL> SQL> --Deal with Null in Rank SQL> SQL> SELECT

 2   prd_type_id, SUM(amount),
 3   RANK() OVER (ORDER BY SUM(amount) DESC) AS rank,
 4   DENSE_RANK() OVER (ORDER BY SUM(amount) DESC) AS dense_rank
 5  FROM all_sales
 6  GROUP BY prd_type_id
 7  ORDER BY prd_type_id;

PRD_TYPE_ID SUM(AMOUNT) RANK DENSE_RANK


----------- ---------- ----------
         1   204217.13          1          1
         2   202662.89          2          2

SQL> SQL> drop table all_sales; Table dropped. SQL> SQL>


 </source>
   
  


decode dense_rank

   <source lang="sql">
 

SQL> SQL> SQL> CREATE TABLE EMP(

 2      EMPNO NUMBER(4) NOT NULL,
 3      ENAME VARCHAR2(10),
 4      JOB VARCHAR2(9),
 5      MGR NUMBER(4),
 6      HIREDATE DATE,
 7      SAL NUMBER(7, 2),
 8      COMM NUMBER(7, 2),
 9      DEPTNO NUMBER(2)
10  );

Table created. SQL> SQL> INSERT INTO EMP VALUES(7369, "SMITH", "CLERK", 7902,TO_DATE("17-DEC-1980", "DD-MON-YYYY"), 800, NULL, 20); 1 row created. SQL> INSERT INTO EMP VALUES(7499, "ALLEN", "SALESMAN", 7698,TO_DATE("20-FEB-1981", "DD-MON-YYYY"), 1600, 300, 30); 1 row created. SQL> INSERT INTO EMP VALUES(7521, "WARD", "SALESMAN", 7698,TO_DATE("22-FEB-1981", "DD-MON-YYYY"), 1250, 500, 30); 1 row created. SQL> INSERT INTO EMP VALUES(7566, "JONES", "MANAGER", 7839,TO_DATE("2-APR-1981", "DD-MON-YYYY"), 2975, NULL, 20); 1 row created. SQL> INSERT INTO EMP VALUES(7654, "MARTIN", "SALESMAN", 7698,TO_DATE("28-SEP-1981", "DD-MON-YYYY"), 1250, 1400, 30); 1 row created. SQL> INSERT INTO EMP VALUES(7698, "BLAKE", "MANAGER", 7839,TO_DATE("1-MAY-1981", "DD-MON-YYYY"), 2850, NULL, 30); 1 row created. SQL> INSERT INTO EMP VALUES(7782, "CLARK", "MANAGER", 7839,TO_DATE("9-JUN-1981", "DD-MON-YYYY"), 2450, NULL, 10); 1 row created. SQL> INSERT INTO EMP VALUES(7788, "SCOTT", "ANALYST", 7566,TO_DATE("09-DEC-1982", "DD-MON-YYYY"), 3000, NULL, 20); 1 row created. SQL> INSERT INTO EMP VALUES(7839, "KING", "PRESIDENT", NULL,TO_DATE("17-NOV-1981", "DD-MON-YYYY"), 5000, NULL, 10); 1 row created. SQL> INSERT INTO EMP VALUES(7844, "TURNER", "SALESMAN", 7698,TO_DATE("8-SEP-1981", "DD-MON-YYYY"), 1500, 0, 30); 1 row created. SQL> INSERT INTO EMP VALUES(7876, "ADAMS", "CLERK", 7788,TO_DATE("12-JAN-1983", "DD-MON-YYYY"), 1100, NULL, 20); 1 row created. SQL> INSERT INTO EMP VALUES(7900, "JAMES", "CLERK", 7698,TO_DATE("3-DEC-1981", "DD-MON-YYYY"), 950, NULL, 30); 1 row created. SQL> INSERT INTO EMP VALUES(7902, "FORD", "ANALYST", 7566,TO_DATE("3-DEC-1981", "DD-MON-YYYY"), 3000, NULL, 20); 1 row created. SQL> INSERT INTO EMP VALUES(7934, "MILLER", "CLERK", 7782,TO_DATE("23-JAN-1982", "DD-MON-YYYY"), 1300, NULL, 10); 1 row created. SQL> SQL> select deptno,

 2         max(decode( dense_rank, 1, sal )) sal1,
 3         max(decode( dense_rank, 2, sal )) sal2,
 4         max(decode( dense_rank, 3, sal )) sal3
 5  from (select deptno, sal,dense_rank() over( partition by deptno order by sal desc) dense_rank from emp)
 6  where dense_rank <= 3
 7  group by deptno
 8  /
   DEPTNO       SAL1       SAL2       SAL3

---------- ---------- ----------
       10       5000       2450       1300
       20       3000       2975       1100
       30       2850       1600       1500

SQL> SQL> SQL> SQL> SQL> SQL> drop table emp; Table dropped. SQL>


 </source>
   
  


DENSE_RANK function

   <source lang="sql">

SQL> SQL> -- create demo table SQL> create table Employee(

 2    ID                 VARCHAR2(4 BYTE)         NOT NULL,
 3    First_Name         VARCHAR2(10 BYTE),
 4    Last_Name          VARCHAR2(10 BYTE),
 5    Start_Date         DATE,
 6    End_Date           DATE,
 7    Salary             Number(8,2),
 8    City               VARCHAR2(10 BYTE),
 9    Description        VARCHAR2(15 BYTE)
10  )
11  /

Table created. SQL> SQL> -- prepare data SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)

 2               values ("01","Jason",    "Martin",  to_date("19960725","YYYYMMDD"), to_date("20060725","YYYYMMDD"), 1234.56, "Toronto",  "Programmer")
 3  /

1 row created. SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)

 2                values("02","Alison",   "Mathews", to_date("19760321","YYYYMMDD"), to_date("19860221","YYYYMMDD"), 9334.78, "Vancouver","Tester")
 3  /

1 row created. SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)

 2                values("03","James",    "Smith",   to_date("19781212","YYYYMMDD"), to_date("19900315","YYYYMMDD"), 4334.78, "Vancouver","Tester")
 3  /

1 row created. SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)

 2                values("04","Celia",    "Rice",    to_date("19821024","YYYYMMDD"), to_date("19990421","YYYYMMDD"), 2334.78, "Vancouver","Manager")
 3  /

1 row created. SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)

 2                values("05","Robert",   "Black",   to_date("19840115","YYYYMMDD"), to_date("19980808","YYYYMMDD"), 6334.78, "Vancouver","Tester")
 3  /

1 row created. SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)

 2                values("06","Linda",    "Green",   to_date("19870730","YYYYMMDD"), to_date("19960104","YYYYMMDD"), 2334.78,"New York",  "Tester")
 3  /

1 row created. SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)

 2                values("07","David",    "Larry",   to_date("19901231","YYYYMMDD"), to_date("19980212","YYYYMMDD"), 1334.78,"New York",  "Manager")
 3  /

1 row created. SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)

 2                values("08","James",    "Cat",     to_date("19960917","YYYYMMDD"), to_date("20020415","YYYYMMDD"), 2334.78,"Vancouver", "Tester")
 3  /

1 row created. SQL> SQL> SQL> SQL> -- display data in the table SQL> select * from Employee

 2  /

ID FIRST_NAME LAST_NAME START_DAT END_DATE SALARY CITY DESCRIPTION


---------- ---------- --------- --------- ---------- ---------- ---------------

01 Jason Martin 25-JUL-96 25-JUL-06 1234.56 Toronto Programmer 02 Alison Mathews 21-MAR-76 21-FEB-86 9334.78 Vancouver Tester 03 James Smith 12-DEC-78 15-MAR-90 4334.78 Vancouver Tester 04 Celia Rice 24-OCT-82 21-APR-99 2334.78 Vancouver Manager 05 Robert Black 15-JAN-84 08-AUG-98 6334.78 Vancouver Tester 06 Linda Green 30-JUL-87 04-JAN-96 2334.78 New York Tester 07 David Larry 31-DEC-90 12-FEB-98 1334.78 New York Manager 08 James Cat 17-SEP-96 15-APR-02 2334.78 Vancouver Tester 8 rows selected. SQL> SQL> SQL> SQL> -- DENSE_RANK function SQL> SQL> SELECT id, first_name, salary,

 2    DENSE_RANK() OVER(ORDER BY salary desc) toprank
 3  FROM employee;

ID FIRST_NAME SALARY TOPRANK


---------- ---------- ----------

02 Alison 9334.78 1 05 Robert 6334.78 2 03 James 4334.78 3 08 James 2334.78 4 04 Celia 2334.78 4 06 Linda 2334.78 4 07 David 1334.78 5 01 Jason 1234.56 6 8 rows selected. SQL> SQL> SQL> -- clean the table SQL> drop table Employee; Table dropped. SQL> / drop table Employee

          *

ERROR at line 1: ORA-00942: table or view does not exist

SQL> SQL> SQL> SQL>


 </source>
   
  


dense_rank() over (order by comm desc nulls last)

   <source lang="sql">
 

SQL> SQL> SQL> CREATE TABLE EMP (EMPNO NUMBER(4) NOT NULL,

 2                    ENAME VARCHAR2(10),
 3                    JOB VARCHAR2(9),
 4                    MGR NUMBER(4),
 5                    HIREDATE DATE,
 6                    SAL NUMBER(7, 2),
 7                    COMM NUMBER(7, 2),
 8                    DEPTNO NUMBER(2));

Table created. SQL> SQL> INSERT INTO EMP VALUES (7369, "SMITH", "CLERK", 7902, TO_DATE("17-DEC-1980", "DD-MON-YYYY"), 800, NULL, 20); 1 row created. SQL> INSERT INTO EMP VALUES (7499, "ALLEN", "SALESMAN", 7698, TO_DATE("20-FEB-1981", "DD-MON-YYYY"), 1600, 300, 30); 1 row created. SQL> INSERT INTO EMP VALUES (7521, "WARD", "SALESMAN", 7698, TO_DATE("22-FEB-1981", "DD-MON-YYYY"), 1250, 500, 30); 1 row created. SQL> INSERT INTO EMP VALUES (7566, "JONES", "MANAGER", 7839, TO_DATE("2-APR-1981", "DD-MON-YYYY"), 2975, NULL, 20); 1 row created. SQL> INSERT INTO EMP VALUES (7654, "MARTIN", "SALESMAN", 7698,TO_DATE("28-SEP-1981", "DD-MON-YYYY"), 1250, 1400, 30); 1 row created. SQL> INSERT INTO EMP VALUES (7698, "BLAKE", "MANAGER", 7839,TO_DATE("1-MAY-1981", "DD-MON-YYYY"), 2850, NULL, 30); 1 row created. SQL> INSERT INTO EMP VALUES (7782, "CLARK", "MANAGER", 7839,TO_DATE("9-JUN-1981", "DD-MON-YYYY"), 2450, NULL, 10); 1 row created. SQL> INSERT INTO EMP VALUES (7788, "SCOTT", "ANALYST", 7566,TO_DATE("09-DEC-1982", "DD-MON-YYYY"), 3000, NULL, 20); 1 row created. SQL> INSERT INTO EMP VALUES (7839, "KING", "PRESIDENT", NULL,TO_DATE("17-NOV-1981", "DD-MON-YYYY"), 5000, NULL, 10); 1 row created. SQL> INSERT INTO EMP VALUES (7844, "TURNER", "SALESMAN", 7698,TO_DATE("8-SEP-1981", "DD-MON-YYYY"), 1500, 0, 30); 1 row created. SQL> INSERT INTO EMP VALUES (7876, "ADAMS", "CLERK", 7788,TO_DATE("12-JAN-1983", "DD-MON-YYYY"), 1100, NULL, 20); 1 row created. SQL> INSERT INTO EMP VALUES (7900, "JAMES", "CLERK", 7698,TO_DATE("3-DEC-1981", "DD-MON-YYYY"), 950, NULL, 30); 1 row created. SQL> INSERT INTO EMP VALUES (7902, "FORD", "ANALYST", 7566,TO_DATE("3-DEC-1981", "DD-MON-YYYY"), 3000, NULL, 20); 1 row created. SQL> INSERT INTO EMP VALUES (7934, "MILLER", "CLERK", 7782,TO_DATE("23-JAN-1982", "DD-MON-YYYY"), 1300, NULL, 10); 1 row created. SQL> SQL> select * from emp;

  EMPNO ENAME      JOB            MGR HIREDATE       SAL     COMM DEPTNO

---------- --------- -------- --------- -------- -------- ------
7369.00 SMITH      CLERK      7902.00 17-DEC-80   800.00              20
7499.00 ALLEN      SALESMAN   7698.00 20-FEB-81  1600.00   300.00     30
7521.00 WARD       SALESMAN   7698.00 22-FEB-81  1250.00   500.00
7566.00 JONES      MANAGER    7839.00 02-APR-81  2975.00              20
7654.00 MARTIN     SALESMAN   7698.00 28-SEP-81  1250.00  1400.00     30
7698.00 BLAKE      MANAGER    7839.00 01-MAY-81  2850.00
7782.00 CLARK      MANAGER    7839.00 09-JUN-81  2450.00              10
  EMPNO ENAME      JOB            MGR HIREDATE       SAL     COMM DEPTNO

---------- --------- -------- --------- -------- -------- ------
7788.00 SCOTT      ANALYST    7566.00 09-DEC-82  3000.00              20
7839.00 KING       PRESIDENT          17-NOV-81  5000.00              10
7844.00 TURNER     SALESMAN   7698.00 08-SEP-81  1500.00      .00     30
7876.00 ADAMS      CLERK      7788.00 12-JAN-83  1100.00              20
7900.00 JAMES      CLERK      7698.00 03-DEC-81   950.00              30
  EMPNO ENAME      JOB            MGR HIREDATE       SAL     COMM DEPTNO

---------- --------- -------- --------- -------- -------- ------
7902.00 FORD       ANALYST    7566.00 03-DEC-81  3000.00              20
7934.00 MILLER     CLERK      7782.00 23-JAN-82  1300.00              10

14 rows selected. SQL> SQL> SQL> SQL> SQL> select ename, comm, dr

 2  from (select ename, comm,
 3        dense_rank() over (order by comm desc nulls last)
 4        dr from emp
 5        where comm is not null)
 6  where dr <= 3
 7  order by comm desc
 8  /

ENAME COMM DR


-------- --------

MARTIN 1400.00 1.00 WARD 500.00 2.00 ALLEN 300.00 3.00 SQL> SQL> SQL> drop table emp; Table dropped. SQL>

 </source>
   
  


dense_rank() over ( partition by deptno order by sal desc )

   <source lang="sql">
 

SQL> SQL> SQL> CREATE TABLE EMP(

 2      EMPNO NUMBER(4) NOT NULL,
 3      ENAME VARCHAR2(10),
 4      JOB VARCHAR2(9),
 5      MGR NUMBER(4),
 6      HIREDATE DATE,
 7      SAL NUMBER(7, 2),
 8      COMM NUMBER(7, 2),
 9      DEPTNO NUMBER(2)
10  );

Table created. SQL> SQL> INSERT INTO EMP VALUES(7369, "SMITH", "CLERK", 7902,TO_DATE("17-DEC-1980", "DD-MON-YYYY"), 800, NULL, 20); 1 row created. SQL> INSERT INTO EMP VALUES(7499, "ALLEN", "SALESMAN", 7698,TO_DATE("20-FEB-1981", "DD-MON-YYYY"), 1600, 300, 30); 1 row created. SQL> INSERT INTO EMP VALUES(7521, "WARD", "SALESMAN", 7698,TO_DATE("22-FEB-1981", "DD-MON-YYYY"), 1250, 500, 30); 1 row created. SQL> INSERT INTO EMP VALUES(7566, "JONES", "MANAGER", 7839,TO_DATE("2-APR-1981", "DD-MON-YYYY"), 2975, NULL, 20); 1 row created. SQL> INSERT INTO EMP VALUES(7654, "MARTIN", "SALESMAN", 7698,TO_DATE("28-SEP-1981", "DD-MON-YYYY"), 1250, 1400, 30); 1 row created. SQL> INSERT INTO EMP VALUES(7698, "BLAKE", "MANAGER", 7839,TO_DATE("1-MAY-1981", "DD-MON-YYYY"), 2850, NULL, 30); 1 row created. SQL> INSERT INTO EMP VALUES(7782, "CLARK", "MANAGER", 7839,TO_DATE("9-JUN-1981", "DD-MON-YYYY"), 2450, NULL, 10); 1 row created. SQL> INSERT INTO EMP VALUES(7788, "SCOTT", "ANALYST", 7566,TO_DATE("09-DEC-1982", "DD-MON-YYYY"), 3000, NULL, 20); 1 row created. SQL> INSERT INTO EMP VALUES(7839, "KING", "PRESIDENT", NULL,TO_DATE("17-NOV-1981", "DD-MON-YYYY"), 5000, NULL, 10); 1 row created. SQL> INSERT INTO EMP VALUES(7844, "TURNER", "SALESMAN", 7698,TO_DATE("8-SEP-1981", "DD-MON-YYYY"), 1500, 0, 30); 1 row created. SQL> INSERT INTO EMP VALUES(7876, "ADAMS", "CLERK", 7788,TO_DATE("12-JAN-1983", "DD-MON-YYYY"), 1100, NULL, 20); 1 row created. SQL> INSERT INTO EMP VALUES(7900, "JAMES", "CLERK", 7698,TO_DATE("3-DEC-1981", "DD-MON-YYYY"), 950, NULL, 30); 1 row created. SQL> INSERT INTO EMP VALUES(7902, "FORD", "ANALYST", 7566,TO_DATE("3-DEC-1981", "DD-MON-YYYY"), 3000, NULL, 20); 1 row created. SQL> INSERT INTO EMP VALUES(7934, "MILLER", "CLERK", 7782,TO_DATE("23-JAN-1982", "DD-MON-YYYY"), 1300, NULL, 10); 1 row created. SQL> SQL> select deptno,ename,sal,

 2         row_number() over (partition by deptno order by sal desc) rn,
 3         rank() over (partition by deptno order by sal desc ) rank,
 4         dense_rank() over ( partition by deptno order by sal desc ) dense_rank
 5  from emp
 6  order by deptno, sal DESC
 7  /
   DEPTNO ENAME             SAL         RN       RANK DENSE_RANK

---------- ---------- ---------- ---------- ----------
       10 KING             5000          1          1          1
          CLARK            2450          2          2          2
          MILLER           1300          3          3          3
       20 SCOTT            3000          1          1          1
          FORD             3000          2          1          1
          JONES            2975          3          3          2
          ADAMS            1100          4          4          3
          SMITH             800          5          5          4
       30 BLAKE            2850          1          1          1
   DEPTNO ENAME             SAL         RN       RANK DENSE_RANK

---------- ---------- ---------- ---------- ----------
       30 ALLEN            1600          2          2          2
          TURNER           1500          3          3          3
          MARTIN           1250          4          4          4
          WARD             1250          5          4          4
          JAMES             950          6          6          5

14 rows selected. SQL> SQL> update emp set sal = 3000 where ename = "JONES"; 1 row updated. SQL> SQL> select deptno,ename,sal,

 2         row_number() over (partition by deptno order by sal desc) rn,
 3         rank() over (partition by deptno order by sal desc ) rank,
 4         dense_rank() over ( partition by deptno order by sal desc ) dense_rank
 5  from emp
 6  order by deptno, sal DESC
 7  /
   DEPTNO ENAME             SAL         RN       RANK DENSE_RANK

---------- ---------- ---------- ---------- ----------
       10 KING             5000          1          1          1
          CLARK            2450          2          2          2
          MILLER           1300          3          3          3
       20 JONES            3000          1          1          1
          SCOTT            3000          2          1          1
          FORD             3000          3          1          1
          ADAMS            1100          4          4          2
          SMITH             800          5          5          3
       30 BLAKE            2850          1          1          1
   DEPTNO ENAME             SAL         RN       RANK DENSE_RANK

---------- ---------- ---------- ---------- ----------
       30 ALLEN            1600          2          2          2
          TURNER           1500          3          3          3
          WARD             1250          4          4          4
          MARTIN           1250          5          4          4
          JAMES             950          6          6          5

14 rows selected. SQL> SQL> drop table emp; Table dropped.


 </source>
   
  


DENSE_RANK()rank items, leaves no gaps when there is a tie

   <source lang="sql">

SQL> CREATE TABLE all_sales (

 2    year INTEGER,
 3    month INTEGER,
 4    prd_type_id INTEGER,
 5    emp_id INTEGER ,
 6    amount NUMBER(8, 2)
 7  );

Table created. SQL> SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,1    ,1          ,21    ,16034.84);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,2    ,1          ,21    ,15644.65);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,3    ,2          ,21    ,20167.83);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,4    ,2          ,21    ,25056.45);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,5    ,2          ,21    ,NULL);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,6    ,1          ,21    ,15564.66);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,7    ,1          ,21    ,15644.65);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,8    ,1          ,21    ,16434.82);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,9    ,1          ,21    ,19654.57);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,10   ,1          ,21    ,21764.19);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,11   ,1          ,21    ,13026.73);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,12   ,2          ,21    ,10034.64);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,1    ,2          ,22    ,16634.84);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,1    ,2          ,21    ,26034.84);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,2    ,1          ,21    ,12644.65);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,3    ,1          ,21    ,NULL);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,4    ,1          ,21    ,25026.45);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,5    ,1          ,21    ,17212.66);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,6    ,1          ,21    ,15564.26);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,7    ,2          ,21    ,62654.82);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,8    ,2          ,21    ,26434.82);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,9    ,2          ,21    ,15644.65);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,10   ,2          ,21    ,21264.19);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,11   ,1          ,21    ,13026.73);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,12   ,1          ,21    ,10032.64);

1 row created. SQL> SQL> select * from all_sales;

     YEAR      MONTH PRD_TYPE_ID     EMP_ID     AMOUNT

---------- ----------- ---------- ----------
     2006          1           1         21   16034.84
     2006          2           1         21   15644.65
     2006          3           2         21   20167.83
     2006          4           2         21   25056.45
     2006          5           2         21
     2006          6           1         21   15564.66
     2006          7           1         21   15644.65
     2006          8           1         21   16434.82
     2006          9           1         21   19654.57
     2006         10           1         21   21764.19
     2006         11           1         21   13026.73
     2006         12           2         21   10034.64
     2005          1           2         22   16634.84
     2005          1           2         21   26034.84
     2005          2           1         21   12644.65
     2005          3           1         21
     2005          4           1         21   25026.45
     2005          5           1         21   17212.66
     2005          6           1         21   15564.26
     2005          7           2         21   62654.82
     2005          8           2         21   26434.82
     2005          9           2         21   15644.65
     2005         10           2         21   21264.19
     2005         11           1         21   13026.73
     2005         12           1         21   10032.64

25 rows selected. SQL> SQL> --DENSE_RANK()rank items, leaves no gaps when there is a tie. SQL> SQL> SELECT

 2   prd_type_id, SUM(amount),
 3   RANK() OVER (ORDER BY SUM(amount) DESC) AS rank,
 4   DENSE_RANK() OVER (ORDER BY SUM(amount) DESC) AS dense_rank
 5  FROM all_sales
 6  WHERE amount IS NOT NULL
 7  GROUP BY prd_type_id
 8  ORDER BY prd_type_id;

PRD_TYPE_ID SUM(AMOUNT) RANK DENSE_RANK


----------- ---------- ----------
         1    227276.5          1          1
         2   223927.08          2          2

SQL> SQL> drop table all_sales; Table dropped. SQL> SQL>


 </source>
   
  


DENSE_RANK() with NULLS FIRST

   <source lang="sql">

SQL> CREATE TABLE all_sales (

 2    year INTEGER,
 3    month INTEGER,
 4    prd_type_id INTEGER,
 5    emp_id INTEGER ,
 6    amount NUMBER(8, 2)
 7  );

Table created. SQL> SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,1    ,1          ,21    ,16034.84);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,2    ,1          ,21    ,15644.65);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,3    ,2          ,21    ,20167.83);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,4    ,2          ,21    ,25056.45);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,5    ,2          ,21    ,NULL);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,6    ,1          ,21    ,15564.66);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,7    ,1          ,21    ,15644.65);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,8    ,1          ,21    ,16434.82);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,9    ,1          ,21    ,19654.57);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,10   ,1          ,21    ,21764.19);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,11   ,1          ,21    ,13026.73);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,12   ,2          ,21    ,10034.64);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,1    ,2          ,22    ,16634.84);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,1    ,2          ,21    ,26034.84);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,2    ,1          ,21    ,12644.65);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,3    ,1          ,21    ,NULL);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,4    ,1          ,21    ,25026.45);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,5    ,1          ,21    ,17212.66);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,6    ,1          ,21    ,15564.26);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,7    ,2          ,21    ,62654.82);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,8    ,2          ,21    ,26434.82);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,9    ,2          ,21    ,NULL);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,10   ,2          ,21    ,NULL);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,11   ,1          ,21    ,NULL);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,12   ,1          ,21    ,NULL);

1 row created. SQL> SQL> select * from all_sales;

     YEAR      MONTH PRD_TYPE_ID     EMP_ID     AMOUNT

---------- ----------- ---------- ----------
     2006          1           1         21   16034.84
     2006          2           1         21   15644.65
     2006          3           2         21   20167.83
     2006          4           2         21   25056.45
     2006          5           2         21
     2006          6           1         21   15564.66
     2006          7           1         21   15644.65
     2006          8           1         21   16434.82
     2006          9           1         21   19654.57
     2006         10           1         21   21764.19
     2006         11           1         21   13026.73
     2006         12           2         21   10034.64
     2005          1           2         22   16634.84
     2005          1           2         21   26034.84
     2005          2           1         21   12644.65
     2005          3           1         21
     2005          4           1         21   25026.45
     2005          5           1         21   17212.66
     2005          6           1         21   15564.26
     2005          7           2         21   62654.82
     2005          8           2         21   26434.82
     2005          9           2         21
     2005         10           2         21
     2005         11           1         21
     2005         12           1         21

25 rows selected. SQL> SQL> -- DENSE_RANK() with NULLS FIRST SQL> SQL> SELECT

 2   prd_type_id, SUM(amount),
 3   DENSE_RANK() OVER (ORDER BY SUM(amount) DESC NULLS FIRST) AS
 4    dense_rank
 5  FROM all_sales
 6  GROUP BY prd_type_id
 7  ORDER BY prd_type_id;

PRD_TYPE_ID SUM(AMOUNT) DENSE_RANK


----------- ----------
         1   204217.13          1
         2   187018.24          2

SQL> SQL> drop table all_sales; Table dropped. SQL> SQL>


 </source>
   
  


DENSE_RANK() with NULLS LAST

   <source lang="sql">

SQL> CREATE TABLE all_sales (

 2    year INTEGER,
 3    month INTEGER,
 4    prd_type_id INTEGER,
 5    emp_id INTEGER ,
 6    amount NUMBER(8, 2)
 7  );

Table created. SQL> SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,1    ,1          ,21    ,16034.84);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,2    ,1          ,21    ,15644.65);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,3    ,2          ,21    ,20167.83);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,4    ,2          ,21    ,25056.45);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,5    ,2          ,21    ,NULL);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,6    ,1          ,21    ,15564.66);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,7    ,1          ,21    ,15644.65);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,8    ,1          ,21    ,16434.82);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,9    ,1          ,21    ,19654.57);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,10   ,1          ,21    ,21764.19);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,11   ,1          ,21    ,13026.73);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2006,12   ,2          ,21    ,10034.64);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,1    ,2          ,22    ,16634.84);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,1    ,2          ,21    ,26034.84);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,2    ,1          ,21    ,12644.65);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,3    ,1          ,21    ,NULL);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,4    ,1          ,21    ,25026.45);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,5    ,1          ,21    ,17212.66);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,6    ,1          ,21    ,15564.26);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,7    ,2          ,21    ,62654.82);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,8    ,2          ,21    ,26434.82);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,9    ,2          ,21    ,15644.65);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,10   ,2          ,21    ,NULL);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,11   ,1          ,21    ,NULL);

1 row created. SQL> insert into all_sales (YEAR,MONTH,PRD_TYPE_ID,EMP_ID,AMOUNT)

 2                  values(2005,12   ,1          ,21    ,NULL);

1 row created. SQL> SQL> select * from all_sales;

     YEAR      MONTH PRD_TYPE_ID     EMP_ID     AMOUNT

---------- ----------- ---------- ----------
     2006          1           1         21   16034.84
     2006          2           1         21   15644.65
     2006          3           2         21   20167.83
     2006          4           2         21   25056.45
     2006          5           2         21
     2006          6           1         21   15564.66
     2006          7           1         21   15644.65
     2006          8           1         21   16434.82
     2006          9           1         21   19654.57
     2006         10           1         21   21764.19
     2006         11           1         21   13026.73
     2006         12           2         21   10034.64
     2005          1           2         22   16634.84
     2005          1           2         21   26034.84
     2005          2           1         21   12644.65
     2005          3           1         21
     2005          4           1         21   25026.45
     2005          5           1         21   17212.66
     2005          6           1         21   15564.26
     2005          7           2         21   62654.82
     2005          8           2         21   26434.82
     2005          9           2         21   15644.65
     2005         10           2         21
     2005         11           1         21
     2005         12           1         21

25 rows selected. SQL> SQL> -- DENSE_RANK() with NULLS LAST SQL> SQL> SELECT

 2   prd_type_id, SUM(amount),
 3   DENSE_RANK() OVER (ORDER BY SUM(amount) DESC NULLS LAST) AS
 4    dense_rank
 5  FROM all_sales
 6  GROUP BY prd_type_id
 7  ORDER BY prd_type_id;

PRD_TYPE_ID SUM(AMOUNT) DENSE_RANK


----------- ----------
         1   204217.13          1
         2   202662.89          2

SQL> SQL> drop table all_sales; Table dropped. SQL> SQL>


 </source>
   
  


rank and dense_rank with group by

   <source lang="sql">
 

SQL> CREATE TABLE sales(

 2    product_id               NUMBER(6),
 3    cid               NUMBER,
 4    time_id               DATE,
 5    sold         NUMBER(3),
 6    amount                NUMBER(10,2),
 7    cost                  NUMBER(10,2)
 8  );

Table created. SQL> SQL> select product_id,

 2         sum(sold),
 3         rank () over (order by sum(sold) desc) as rank,
 4         dense_rank () over (order by sum(sold) desc) as dense_rank
 5  from sales
 6  where to_char(time_id, "yyyy-mm") = "2001-06"
 7  group by product_id;

no rows selected SQL> SQL> drop table sales; Table dropped.


 </source>
   
  


Use DENSE_RANK() to get the top rank

   <source lang="sql">

SQL> SQL> SQL> -- create demo table SQL> create table Employee(

 2    ID                 VARCHAR2(4 BYTE)         NOT NULL,
 3    First_Name         VARCHAR2(20 BYTE),
 4    Last_Name          VARCHAR2(20 BYTE),
 5    Start_Date         DATE,
 6    End_Date           DATE,
 7    Salary             Number(8,2),
 8    City               VARCHAR2(20 BYTE),
 9    Description        VARCHAR2(80 BYTE)
10  )
11  /

Table created. SQL> SQL> -- prepare data SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)

 2               values ("01","Jason",    "Martin",  to_date("19960725","YYYYMMDD"), to_date("20060725","YYYYMMDD"), 1234.56, "Toronto",  "Programmer")
 3  /

1 row created. SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)

 2                values("02","Alison",   "Mathews", to_date("19760321","YYYYMMDD"), to_date("19860221","YYYYMMDD"), 2234.78, "Vancouver","Tester")
 3  /

1 row created. SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)

 2                values("03","James",    "Smith",   to_date("19781212","YYYYMMDD"), to_date("19900315","YYYYMMDD"), 2324.78, "Vancouver","Tester")
 3  /

1 row created. SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)

 2                values("04","Celia",    "Rice",    to_date("19821024","YYYYMMDD"), to_date("19990421","YYYYMMDD"), 3334.78, "Vancouver","Manager")
 3  /

1 row created. SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)

 2                values("05","Robert",   "Black",   to_date("19840115","YYYYMMDD"), to_date("19980808","YYYYMMDD"), 4334.78, "Vancouver","Tester")
 3  /

1 row created. SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)

 2                values("06","Linda",    "Green",   to_date("19870730","YYYYMMDD"), to_date("19960104","YYYYMMDD"), 5334.78,"New York",  "Tester")
 3  /

1 row created. SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)

 2                values("07","David",    "Larry",   to_date("19901231","YYYYMMDD"), to_date("19980212","YYYYMMDD"), 6334.78,"New York",  "Manager")
 3  /

1 row created. SQL> insert into Employee(ID, First_Name, Last_Name, Start_Date, End_Date, Salary, City, Description)

 2                values("08","James",    "Cat",     to_date("19960917","YYYYMMDD"), to_date("20020415","YYYYMMDD"), 7334.78,"Vancouver", "Tester")
 3  /

1 row created. SQL> SQL> SQL> SQL> -- display data in the table SQL> select * from Employee

 2  /

ID FIRST_NAME LAST_NAME START_DAT END_DATE SALARY CITY DESCRIPTION


-------------------- -------------------- --------- --------- ---------- -------------------- --------------------------------------------------------------------------------

01 Jason Martin 25-JUL-96 25-JUL-06 1234.56 Toronto Programmer 02 Alison Mathews 21-MAR-76 21-FEB-86 2234.78 Vancouver Tester 03 James Smith 12-DEC-78 15-MAR-90 2324.78 Vancouver Tester 04 Celia Rice 24-OCT-82 21-APR-99 3334.78 Vancouver Manager 05 Robert Black 15-JAN-84 08-AUG-98 4334.78 Vancouver Tester 06 Linda Green 30-JUL-87 04-JAN-96 5334.78 New York Tester 07 David Larry 31-DEC-90 12-FEB-98 6334.78 New York Manager 08 James Cat 17-SEP-96 15-APR-02 7334.78 Vancouver Tester 8 rows selected. SQL> SQL> SQL> SELECT id, first_name, salary,

 2    DENSE_RANK() OVER(ORDER BY salary desc) toprank
 3  FROM employee;

ID FIRST_NAME SALARY TOPRANK


-------------------- ---------- ----------

08 James 7334.78 1 07 David 6334.78 2 06 Linda 5334.78 3 05 Robert 4334.78 4 04 Celia 3334.78 5 03 James 2324.78 6 02 Alison 2234.78 7 01 Jason 1234.56 8 8 rows selected. SQL> SQL> SQL> -- clean the table SQL> drop table Employee

 2  /

Table dropped. SQL> SQL> SQL> SQL> SQL>


 </source>
   
  


Use rank and dense_rank in subquery

   <source lang="sql">
 

SQL> CREATE TABLE sales(

 2    product_id            NUMBER(6),
 3    cid           NUMBER,
 4    time_id               DATE,
 5    sold         NUMBER(3),
 6    amount                NUMBER(10,2),
 7    cost                  NUMBER(10,2)
 8  );

Table created. SQL> SQL> select * from

 2    (select product_id,
 3           sum(sold),
 4           rank () over (order by sum(sold) desc) as rank,
 5           dense_rank () over (order by sum(sold) desc) as dense_rank
 6    from sales
 7    where to_char(time_id, "yyyy-mm") = "2001-06"
 8    group by product_id)
 9  where rank < 11;

no rows selected SQL> SQL> SQL> drop table sales; Table dropped.


 </source>