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?

Creation of indexes, Creation of Indexes Automatically: When a primar...

Creation of Indexes Automatically: When a primary key or Unique constraint is show in a table definition then a unique index is formed automatically. Manually: User can

Explain normalization, What is Normalization? Database normalization is...

What is Normalization? Database normalization is a data design and organization method applied to data structures based on rules that help building relational databases. In rel

Explain the concept of modeling with objects, Explain the concept of Modeli...

Explain the concept of Modeling With Objects A model is a conceptual representation of a specification, design or system from a particular point of view. A modelling language

What is authorization graph, What is authorization graph? Passing of au...

What is authorization graph? Passing of authorization from single user to another can be shown by an authorization graph.

Implementing a data mining algorithm, i need to implememnt a treee based mi...

i need to implememnt a treee based mining algorithm. do you have an expert that can do that?

Rules of data normalisation, Rules Of Data Normalisation  Let us now su...

Rules Of Data Normalisation  Let us now summarise Normalisation with the help of various clean rules. The following are the necessary rules for the Normalisation process: 1.

Define 2nf normal form, 2NF Normal Form : A relation schema process R i...

2NF Normal Form : A relation schema process R is in 2NF if it is in 1NF and each non-prime attribute A in R is fully functionally related on primary key. Second normal form (2N

List out user authorization to modify the database schema, List out various...

List out various user authorization to modify the database schema. a)  Index authorization b)  Resource authorization c)  Alteration authorization d)  Drop authorizat

Describe second normal and third normal form, Database Management Systems ...

Database Management Systems 1. Explain SQL Server 2000 Architecture with diagram. 2. Describe Second Normal and Third Normal Form. 3. Explain about query engine and stora

Marketing interface, as a customer service employee explain five measures y...

as a customer service employee explain five measures you would recommend to make even a displeased students patronize the school canteen

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