What is null described testing for null in sql?, Database Management System

Assignment Help:

What is NULL? Give an example to described testing for NULL in SQL?

The NULL SQL keyword is used to represent either a missing value or a value which is not applicable in a relational table. Consider there is a relation:

Person(id, name, address, phone)
Now to search ids and names of person who do not have a phone is:
Select id, name
from Person
where phone is null

Related Discussions:- What is null described testing for null in sql?

Working and processing files, 1. Define each of the following IN YOUR OWN ...

1. Define each of the following IN YOUR OWN WORDS: (a) File: (b) Record: (c) Field: (d) Primary Key: (e) Secondary Key: 2. A travel agency wants t

Relationship between security and integrity, Relationship between Security ...

Relationship between Security and Integrity: Database security usually refers to access, while database integrity refers to avoidance of accidental loss of consistency. But usually

Computing the closure of a set of functional dependency, What is meant by c...

What is meant by computing the closure of a set of functional dependency? The closure of F denoted by F + is the set of functional dependencies logically implied by F.

Which model is record based logical model, Which model is record based logi...

Which model is record based logical model? Network Modelis basically known as record based logical model.

Er diagram, Draw an ER diagram for company''s database schema

Draw an ER diagram for company''s database schema

Determine the strong and weak entity, Determine the Strong and Weak Entity ...

Determine the Strong and Weak Entity Based on the method of foreign key, there might be arise a situation when we have to relate an entity having a primary key of its own and a

Explain difference between volatile, Explain the difference between the thr...

Explain the difference between the three storage types - volatile, non volatile and stable. Ans: Volatile storage: if storage media loses data while power goes off,

State the functional approach of object oriented methods, State the functio...

State the functional approach of object oriented methods Moving from a functional approach to an object oriented one needs a translation of functional model elements into objec

What is a dataset, What is a dataset? A dataset is an in-memory databas...

What is a dataset? A dataset is an in-memory database that is disconnected from any regular database, but has all the significant characteristics of a regular database. Dataset

Analyzing association traversal, Analyzing Association Traversal Assoc...

Analyzing Association Traversal Association Traversal shall be understood properly for the association design explanation. Analyzing association traversal means analyzing tra

Write Your Message!

Name

Email id

Message

Verfication Code

User Account

All Pages