• Skip to main content
  • Skip to primary sidebar
  • Skip to secondary sidebar
  • Skip to footer

Computer Notes

Library
    • Computer Fundamental
    • Computer Memory
    • DBMS Tutorial
    • Operating System
    • Computer Networking
    • C Programming
    • C++ Programming
    • Java Programming
    • C# Programming
    • SQL Tutorial
    • Management Tutorial
    • Computer Graphics
    • Compiler Design
    • Style Sheet
    • JavaScript Tutorial
    • Html Tutorial
    • Wordpress Tutorial
    • Python Tutorial
    • PHP Tutorial
    • JSP Tutorial
    • AngularJS Tutorial
    • Data Structures
    • E Commerce Tutorial
    • Visual Basic
    • Structs2 Tutorial
    • Digital Electronics
    • Internet Terms
    • Servlet Tutorial
    • Software Engineering
    • Interviews Questions
    • Basic Terms
    • Troubleshooting
Menu

Header Right

Home » Sql » Queries » SQL ISNULL() Function
Next →
← Prev

SQL ISNULL() Function

By Dinesh Thakur

Null is a special marker used in Structured Query Language (SQL) to indicate that a data value does not exist in the database. NULL means missing information and inapplicable information”. NULL values represent missing unknown data. By default, a table column can hold NULL values.

If a column in a table is optional, we can insert a new record or update an existing record without adding a value to this column. This means that the field will be saved with a NULL value.

NULL values are treated differently from other values. It is not same as ZERO or BLANK. NULL means there exist some value but still it’s unknown. Whereas The NOT NULL constraint allows a column not to accept NULL values. This specifies that NOT NULL Constraint enforce the field to accept a value. This means that you cannot insert a new record, or update a record without adding a value to this field.

List the Employee NAME, SAL who doesn’t work under any Manager

SQL> SELECT ENAME, SAL FROM EMP WHERE MGR IS NULL;

List the Employee NAME, SAL whose salary greater than 3000 and getting no Commission.

SQL> SELECT ENAME, SAL FROM EMP WHERE SAL>3000 AND COMM IS NULL;

List the Employee NAME, SAL who is getting commission

SQL> SELECT ENAME, SAL FROM EMP WHERE COMM IS NOT NULL;

 

You’ll also like:

  1. MySql ISNULL Function in Java Servlet
  2. SQL DATE Function
  3. SQL NVL Function
  4. SQL GETDATE() Function
  5. SQL CAST() Function
Next →
← Prev
Like/Subscribe us for latest updates     

About Dinesh Thakur
Dinesh ThakurDinesh Thakur holds an B.C.A, MCDBA, MCSD certifications. Dinesh authors the hugely popular Computer Notes blog. Where he writes how-to guides around Computer fundamental , computer software, Computer programming, and web apps.

Dinesh Thakur is a Freelance Writer who helps different clients from all over the globe. Dinesh has written over 500+ blogs, 30+ eBooks, and 10000+ Posts for all types of clients.


For any type of query or something that you think is missing, please feel free to Contact us.


Primary Sidebar

SQL Tutorials

SQL Tutorials

  • SQL - Home
  • SQL - Select
  • SQL - Create
  • SQL - View
  • SQL - Sub Queries
  • SQL - Update
  • SQL - Delete
  • SQL - Order By
  • SQL - Select Distinct
  • SQL - Group By
  • SQL - Where Clause
  • SQL - Select Into
  • SQL - Insert Into
  • SQL - Sequence
  • SQL - Constraints
  • SQL - Alter
  • SQL - Date
  • SQL - Foreign Key
  • SQL - Like Operator
  • SQL - CHECK Constraint
  • SQL - Exists Operator
  • SQL - Drop Table
  • SQL - Alias Syntax
  • SQL - Primary Key
  • SQL - Not Null
  • SQL - Union Operator
  • SQL - Unique Constraint
  • SQL - Between Operator
  • SQL - Having Clause
  • SQL - Isnull() Function
  • SQL - IN Operator
  • SQL - Default Constraint
  • SQL - Minus Operator
  • SQL - Intersect Operator
  • SQL - Triggers
  • SQL - Cursors

Advanced SQL

  • SQL - Joins
  • SQL - Index
  • SQL - Self Join
  • SQL - Outer Join
  • SQL - Join Types
  • SQL - Cross Join
  • SQL - Left Outer Join
  • SQL - Right Join
  • SQL - Drop Index
  • SQL - Inner Join
  • SQL - Datediff() Function
  • SQL - NVL Function
  • SQL - Decode Function
  • SQL - Datepart() Function
  • SQL - Count Function
  • SQL - Getdate() Function
  • SQL - Cast() Function
  • SQL - Round() Function

Other Links

  • SQL - PDF Version

Footer

Basic Course

  • Computer Fundamental
  • Computer Networking
  • Operating System
  • Database System
  • Computer Graphics
  • Management System
  • Software Engineering
  • Digital Electronics
  • Electronic Commerce
  • Compiler Design
  • Troubleshooting

Programming

  • Java Programming
  • Structured Query (SQL)
  • C Programming
  • C++ Programming
  • Visual Basic
  • Data Structures
  • Struts 2
  • Java Servlet
  • C# Programming
  • Basic Terms
  • Interviews

World Wide Web

  • Internet
  • Java Script
  • HTML Language
  • Cascading Style Sheet
  • Java Server Pages
  • Wordpress
  • PHP
  • Python Tutorial
  • AngularJS
  • Troubleshooting

 About Us |  Contact Us |  FAQ

Dinesh Thakur is a Technology Columinist and founder of Computer Notes.

Copyright © 2025. All Rights Reserved.

APPLY FOR ONLINE JOB IN BIGGEST CRYPTO COMPANIES
APPLY NOW