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?

Explain the process-oriented decomposition, Breaking into Subsystems D...

Breaking into Subsystems Decomposition is a significant technique for coping with complexity based on idea of divide and conquers. In dividing a problem into sub problems, the

Business process model, Consider a research paper submission process. The p...

Consider a research paper submission process. The process starts when an author submits a draft research paper (the paper may have up to 3 authors) to the chair of the organizing c

What is e-r model, What is E-R model? This data model is based on real ...

What is E-R model? This data model is based on real world that having of basic objects called entities and of relationship between these objects. Entities are explained in a da

Explain what is aggregation, Explain what is Aggregation? Aggregation:...

Explain what is Aggregation? Aggregation: Aggregation is an significant concept in database design whereas composite objects could be modelled during the design of database a

How to deal with the authentication problem, Most computer systems authenti...

Most computer systems authenticate users by asking them for the user name and password. However, the user names and passwords often can be guessed by hackers. Suggest an automated,

File organisation in dbms, File Organisation In Dbms Introduction ...

File Organisation In Dbms Introduction Databases are used to store information. Usually, the principal operations we have to perform on database are those relating to:

Describe the most important classes of parallel machines, Question 1 Discu...

Question 1 Discuss the classification of DBMS based on location of database Question 2 Explain with examples different SQL commands used for creating and deleting relations.

ERD, A student entity type has the following attributes,name..

A student entity type has the following attributes,name..

Define direct file organization, Define Direct file organization? The d...

Define Direct file organization? The direct file organization is employed to enhance the performance in accessing the records than sequential file organization. In direct file

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd