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 sequential file organization, Describe sequential file organizatio...

Describe sequential file organization.  Explain the rules for (i)  Inserting a new record. (ii)  Deleting an existing record.          Ans:A sequential f

Data modelling, Law Associates is a large legal practice based in Sydney.  ...

Law Associates is a large legal practice based in Sydney.  You have been asked to design a data model for the practice based upon the following specification: The practice emplo

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

Illustrate the collaboration and relationship diagram, Illustrate the colla...

Illustrate the collaboration and relationship diagram A collaboration is the society of interfaces, classes and other elements which work together to provide some cooperative b

Give the levels of data abstraction, Give the levels of data abstraction? ...

Give the levels of data abstraction? There are three levels of Data Abstraction a) Physical level b) logical level c) view level

Database, why are older data models are being replaced by new data models

why are older data models are being replaced by new data models

ER model, coventions for displaying an ER schema as ER diagram

coventions for displaying an ER schema as ER diagram

Command line interfaces, Command Line Interfaces: These are interactive int...

Command Line Interfaces: These are interactive interfaces, character-based that let you use the complete power and functionality of the DBMS query language directly. They permit yo

Describe the basic steps involved in recovery, Question: One of the tas...

Question: One of the tasks a database management system must perform is to ensure that the data is still intact in the face of software and hardware failure. This task is known

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