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?

converting eerd, Create centralized relational database using Top down met...

Create centralized relational database using Top down method- Construction of Logical Model: Translation EERD into Relational Schema: Use the 8 steps algorithm of converting EERD

What three major types of actions includes databases, What three major type...

What three major types of actions includes databases? Briefly discuss these The three major types of actions including databases are: (i) Defining: It includes specifyin

Relational model, A model in database system mostly defines the organisatio...

A model in database system mostly defines the organisation of data or structure and a set of operations on that data. Relational model is a easy model in which database is represen

Dealing with constraints violation, If the deletion violates referential in...

If the deletion violates referential integrity constraint, then three alternatives are available: Default option: - refuse the deletion. It is the job of the DBMS to describ

What are the authentication modes in sql server, What are the authenticatio...

What are the authentication modes in SQL Server? How can it be changed? Windows mode and Mixed Mode - SQL and Windows. To alter authentication mode in SQL Server click Start, P

Describe difference between a one-to-many and a many-to-many, Describe the ...

Describe the difference between a one-to-many and a many-to-many relationship. Which logical data structures comprise one-to-many and which comprise many-to-many relationship?

What do you mean through integrity constraints, What do you mean through in...

What do you mean through integrity constraints? Integrity Constraints -An integrity constraint is a condition specified on a database schema and restricts the data in which

Explain data models namely relational network - hierarchical, Explain the t...

Explain the three data models namely relational, network and hierarchical and evaluate their relative advantages and disadvantages. Hierarchical Model: In hierarchical model, da

To delete a particular column in a relation which command, To delete a part...

To delete a particular column in a relation which command is used ? To delete a particular column in a relation ALTER command is used.

Business process model, Consider a research paper submission process. The p...

Consider a research paper submission process. The process starts when an author submits a draft research paper (the paper may have up to 3 authors) to the chair of the organizing c

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