What is primary key, Database Management System

Assignment Help:

What is Primary key?

Primary Key - Primary key is one of the candidate keys which uniquely identifies each row in the relation.


Related Discussions:- What is primary key

Illustrate the fifth normal form, Fifth Normal Form (5NF) These relatio...

Fifth Normal Form (5NF) These relations still have a difficulty. While defining the 4NF we mentioned that all the attributes depend upon each other. Whereas creating the two ta

How can you map null values to other values while display, How can you map ...

How can you map NULL values to other values while display? IF( ) , IFNULL( ) keywords are used to do so. They are 'LIMIT' is used for the following kinds of problems: 1) Ans

Define the notation for classes and atrributes, Define the notation for cla...

Define the notation for classes and atrributes The notation for class, attribute, and operations are shown below:     Figure: Class with attributes and operations A

List the armstrong axioms for functional dependencies, List the Armstrong's...

List the Armstrong's axioms for functional dependencies.  What do you understand by soundness and completeness of these axioms?      Ans: The Armstrong's axioms are: F1:

Define boyce codd normal form, Define Boyce codd normal form A relation...

Define Boyce codd normal form A relation schema R is in BCNF with respect to a set F of functional dependencies if, for all functional dependencies in F + of the form.α ->β.

ERD, online eductional management system ke diagram

online eductional management system ke diagram

What is recovery?, What Is Recovery?  During the life of a transaction, ...

What Is Recovery?  During the life of a transaction, i.e., a after the start of a transaction but before the transaction commits, various changes may be made in a database state

Describe embedded query language, Describe Embedded Query Language? Emb...

Describe Embedded Query Language? Embedded Query Language - A query language (e.g., SQL) can be implemented in two ways. It can be used interactively or embedded within a host

Explain the exists and unique functions of sql, Explain the EXISTS and UNIQ...

Explain the EXISTS and UNIQUE functions of SQL. Give an example for each? EXISTS: The EXISTS function takes one parameter that is a SQL statement. If any records exist which

In e-r diagram how derived attribute are represented, In E-R Diagram how de...

In E-R Diagram how derived attribute are represented ? In E-R Diagram By Dashed ellipse derived attribute are represented.

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