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?

Designing the fields in the data base, Designing the fields in the data bas...

Designing the fields in the data base The following are the considerations one has to remain in mind while designing the fields in the data base. Coding, compression, en

Construct substantial data model, PART MARKING: We will only mark TWO of t...

PART MARKING: We will only mark TWO of the four questions below but you must submit answers to all four. We will choose the questions we mark randomly and we will supply you with

Relational schema, crete a data base relationship model Entity: ...

crete a data base relationship model Entity: Students; Professors; Dormitories buildings; Attributes of students: Name; Address; Dorm;

Scope of traffic data management, A TDMS project plan is not a typical Info...

A TDMS project plan is not a typical Information Technology project plan; therefore, a traffic data project has several unique characteristics: Traffic data management system

Describe the composite key, Describe the Composite Key Composite Key: ...

Describe the Composite Key Composite Key: Sometimes one key is not enough to uniquely recognize a row. E.g. in a single class Roll is enough to search a student, but in the w

Explain the dependency relationship of object oriented, Explain the depende...

Explain the dependency relationship of object oriented A dependency is a relationship which states that a change in specification of one thing can affect another thing, but n

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

What is storage manager, What is storage manager? A storage manager is ...

What is storage manager? A storage manager is a program module that gives the interface among the low level data keeps in a database and the application programs and queries su

Illustrate about the advanced object design, Illustrate about the advanced ...

Illustrate about the advanced object design Advanced object design is a complex task. The objects discovered through analysis serve as a skeleton of design. The operations reco

Domain, domain

domain

Write Your Message!

Name

Email id

Message

Verfication Code

User Account

All Pages