Differences among the candidate keys and the primary key, Database Management System

Assignment Help:

Discuss the differences among the candidate keys and the primary key of a relation. Give instance to describe your answer?

A candidate key is one that can be used as primary key which not null and unique constraint both is holding true. In short all primary keys are definitely candidate keys. That is one of the candidate keys is selected as primary key.


Related Discussions:- Differences among the candidate keys and the primary key

Explain the terms primary key, Explain the terms primary key, candidate key...

Explain the terms primary key, candidate key, alternate key and secondary key. In the given table identify every key? STUDENT(SID,Regno, Name, City) Primary Key: The prim

Search the name department number and salary of employees , Example : Searc...

Example : Search the name, department number and salary of employees drawing minimum salary in that department. SELECT ENAME, SAL, DEPTNO  FROM EMP WHERE SAL IN (SELECT MI

Derived horizontal fragmentation, atient(PNumber, Name, NHS_no, Amount_due,...

atient(PNumber, Name, NHS_no, Amount_due, DNO, Doctor, Medical_Treatment), relation of schema Staff(StaffNum, Name, DNO, Task) and relation of schema Dept(DNO, Name, Location, Dire

What function divides one numeric expression, What function divides one num...

What function divides one numeric expression by another and returns the remainder? MOD function divides one numeric expression by another and returns the remainder.

Define atom of domain relational calculus, Define Atom of domain relational...

Define Atom of domain relational calculus An atom has the outline 1 , x 2 , ... , x n > -> r , in which r stands for a relation on n attributes and x 1 , x 2 , ... , x n ar

HRM, is Chipo carrying his baby

is Chipo carrying his baby

What are costs to be considere when transaction is roll back, What are the ...

What are the costs to be considered when a transaction has to be rolled back when recovering from deadlock?         Ans: A few transaction will must rolled back (made a victim)

Database recovery and security, Database Recovery And Security Introdu...

Database Recovery And Security Introduction In this part we will introduce two main issues relating to database management systems. A computer system suffers from dissi

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