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?

Describe a technique for direct search, Describe a technique for direct sea...

Describe a technique for direct search? Explain how data is stored within a file so which direct searching can be performed. For a file of unordered fixed length records by u

What is a candidate key, What is a candidate key? Minimal super keys ar...

What is a candidate key? Minimal super keys are known as candidate keys.

Deletion operation - update operations, By using the delete operation some ...

By using the delete operation some consisting records can be deleted from a relation. To delete some definite records from the database a condition is also specified based on which

Benefits and drawbacks of sequential file organisation, Benefits of Sequent...

Benefits of Sequential File Organisation It is quick and efficient when dealing with huge volumes of data that require being processed periodically (batch system). Dra

Define one-way associations using pointers, One-way Associations If an...

One-way Associations If an association is only traversed in single direction, then it is known as one-way association. It is implemented as a pointer or an attribute which con

Homework, can you resolve this for me please? Database Management Systems ...

can you resolve this for me please? Database Management Systems Homework 1 The following relations are given (primary keys are underlined): PLAY-ACTOR(AId, Name, Nationality, Birt

System analysis plannig and control, milestone assignment

milestone assignment

What are the various states of transaction process, What are the various st...

What are the various states through which a transaction passes through in its lifetime? Briefly discuss all the events that causes transition from one state to another. Ans:

Physical dbms architecture, PHYSICAL DBMS ARCHITECTURE The physical ...

PHYSICAL DBMS ARCHITECTURE The physical architecture defines the software components used to process and enter data, and how these software components are related and interc

Example database application, We will explain here an example database appl...

We will explain here an example database application having COLLEGE database and use it in showing several E-R modelling concepts. College database remains track of faculty, Stu

Write Your Message!

Name

Email id

Message

Verfication Code

User Account

All Pages