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?

RDBMS, DISADVANTAGES OF RDBMS

DISADVANTAGES OF RDBMS

Create the logical database schema, 1.  Based on the dependency diagram, cr...

1.  Based on the dependency diagram, create a database whose tables are in at least 2NF, showing the dependency diagram for each table (as shown in class).  Label the types of depe

What are the advantages of logical databases, What are the advantages of Lo...

What are the advantages of Logical Databases? It offers a simple-to-use selection screens.  You can change the pre-generated selection screen to your needs.  It offers check f

Determine the subsystem design issue, Determine the Other System Design Iss...

Determine the Other System Design Issue How to realise subsystems; through hardware or software? How is object model mapped on chosen hardware software? Mapping

Define the term e-government, Question: (a) Define the term e-Governme...

Question: (a) Define the term e-Government and briefly explain, using appropriate examples, the aspects it covers. (b) Give four reasons as to why a country should adopt e

Determine the term- active values, Determine the term- Active values An...

Determine the term- Active values An active value is that has dependent values. Every dependent value registers itself with active value that contains a set of dependent values

Forward recovery (redo), Forward Recovery (Redo): In this system the commit...

Forward Recovery (Redo): In this system the committed changes made by a transaction are reapplied to a previous copy of the database.                          In simpler

Relational database implementation, You must implement the entity relations...

You must implement the entity relationship model provided in the model solution to Assignment 1. The model solution will be released on the course website approximately TWO (2) we

Commercial database architecture, At its most essential level the DBMS arch...

At its most essential level the DBMS architecture can be divide into two parts: the back end and the front end. The back end is responsible for managing the physical database an

Distributed database management system, Question (a) Differentiate betw...

Question (a) Differentiate between the following terms: (i) Distributed Database v/s Distributed Database management System (ii) Homogeneous Distributed Database v/s Hete

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