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?

What is the function of a domain, What is the function of a Domain? A d...

What is the function of a Domain? A domain defines the technical settings of a table field. A domain describes a value range, which sets the permissible data values for the

Need for multiple access paths, Need for Multiple Access Paths In pract...

Need for Multiple Access Paths In practice, most of the online information systems need the support of multi-key files. For example, consider a banking database application hav

Er diagram, er diagram of sport

er diagram of sport

SQL, Ask Write the SQL code that will create the table structure for a tabl...

Ask Write the SQL code that will create the table structure for a table named EMP _1. This table is a subset of the EMPLOYEE table. The basic EMP_1 table structure is summarized in

Explain p command in the respect of qbe, Explain P command in the respect o...

Explain P command in the respect of QBE? P: It is the command in which is used to print (logically display) the value of the attribute in whose cell it is writ

Explain the use of constraints in functional model, Explain the use of cons...

Explain the use of constraints in functional model with suitable example. A constraint shows relationship between two objects at same time, or among various values of the sam

Subclassing, In the ER diagram, one example of subclassing is depicted foll...

In the ER diagram, one example of subclassing is depicted following the Services entity. The subclasses Item Based and Time Based are created. The entity Services gains the attribu

Database, real life situations where database management system are most su...

real life situations where database management system are most suitable

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

Explain what is Aggregation ? Aggregation: This is used whenever we intend to show a relationship between an entity and the relationship. There is no provision for this in th

Explain derived and non-derived attribute, Explain Derived and Non-Derived ...

Explain Derived and Non-Derived Attribute? In few cases, two or more attribute values are related, for instance, Age and BirthDate attributes of a person. For specific person e

Write Your Message!

Name

Email id

Message

Verfication Code

User Account

All Pages