DENSE_RANK NULL value : DENSE_RANK « Analytical Functions « Oracle PL/SQL Tutorial

Home
Oracle PL/SQL Tutorial
1.Introduction
2.Query Select
3.Set
4.Insert Update Delete
5.Sequences
6.Table
7.Table Joins
8.View
9.Index
10.SQL Data Types
11.Character String Functions
12.Aggregate Functions
13.Date Timestamp Functions
14.Numerical Math Functions
15.Conversion Functions
16.Analytical Functions
17.Miscellaneous Functions
18.Regular Expressions Functions
19.Statistical Functions
20.Linear Regression Functions
21.PL SQL Data Types
22.PL SQL Statements
23.PL SQL Operators
24.PL SQL Programming
25.Cursor
26.Collections
27.Function Procedure Packages
28.Trigger
29.SQL PLUS Session Environment
30.System Tables Data Dictionary
31.System Packages
32.Object Oriented
33.XML
34.Large Objects
35.Transaction
36.User Privilege
Oracle PL/SQL Tutorial » Analytical Functions » DENSE_RANK 
16.5.5.DENSE_RANK NULL value

RANK() and DENSE_RANK() assign the highest rank of 1 to null values in descending rankings.

In descending rankings, the DESC is used in the OVER clause.

RANK() and DENSE_RANK() assign the lowest rank in ascending rankings.

In ascending rankings, ASC is used in the OVER clause.

SQL>
SQL>
SQL>
SQL> -- create demo table
SQL> create table Employee(
  2    ID                 VARCHAR2(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  /

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'), 6661.78'Vancouver','Tester')
  3  /

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'), 6544.78'Vancouver','Tester')
  3  /

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'), 2344.78'Vancouver','Manager')
  3  /

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'), 2334.78'Vancouver','Tester')
  3  /

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'), 4322.78,'New York',  'Tester')
  3  /

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'), 7897.78,'New York',  'Manager')
  3  /

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'), NULL,'Vancouver', 'Tester')
  3  /

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    6661.78 Vancouver  Tester
03   James      Smith      12-DEC-78 15-MAR-90    6544.78 Vancouver  Tester
04   Celia      Rice       24-OCT-82 21-APR-99    2344.78 Vancouver  Manager
05   Robert     Black      15-JAN-84 08-AUG-98    2334.78 Vancouver  Tester
06   Linda      Green      30-JUL-87 04-JAN-96    4322.78 New York   Tester
07   David      Larry      31-DEC-90 12-FEB-98    7897.78 New York   Manager
08   James      Cat        17-SEP-96 15-APR-02            Vancouver  Tester

rows selected.

SQL>
SQL>
SQL> SELECT
  2   city, SUM(salary),
  3   RANK() OVER (ORDER BY SUM(salaryDESCAS rank,
  4   DENSE_RANK() OVER (ORDER BY SUM(salaryDESCAS dense_rank
  5  FROM employee
  6  GROUP BY city
  7  ORDER BY city;

CITY       SUM(SALARY)       RANK DENSE_RANK
---------- ----------- ---------- ----------
New York      12220.56          2          2
Toronto        1234.56          3          3
Vancouver     17886.12          1          1

SQL>
SQL>
SQL>
SQL> -- clean the table
SQL> drop table Employee
  2  /

Table dropped.
16.5.DENSE_RANK
16.5.1.Using the DENSE_RANK()
16.5.2.The DENSE_RANK and tie
16.5.3.See the top five salaries
16.5.4.Use ROW_NUMBER(), RANK() and DENSE_RANK() together
16.5.5.DENSE_RANK NULL value
16.5.6.NULLS LAST
16.5.7.NULLS FIRST
16.5.8.decode dense_rank
java2s.com  | Contact Us | Privacy Policy
Copyright 2009 - 12 Demo Source and Support. All rights reserved.
All other trademarks are property of their respective owners.