Define entity integrity and referential integrity, Database Management System

Assignment Help:

Define entity integrity and referential integrity.  How does SQL allow specification of  these?

Ans: Entity Integrity Rule- If the attribute A of relation R is a prime attribute of R after that A cannot accept null values. 

Referential Integrity Rule- In referential integrity, it is made sure that a value that appears in one relation for a given set of attributes as well appears for a particular set of attributes in another relation.

 In SQL, referential integrity and entity integrity rules are implemented as constraints on the relation known as reference Key constraint and primary Key constraint correspondingly.

 These constraints can be fixed with relation at the time of creation of the relations or after the creation of the relations by altering the definition of the relations. For instance:

 

600_Define entity integrity and referential integrity.png

 


Related Discussions:- Define entity integrity and referential integrity

Entity-relationship diagram, 1. Item based services will be charged fixed p...

1. Item based services will be charged fixed prices, and time-based will be charged variably depending on time. Such as per hour. Item-based: Fixed, pedicure, waxing, threading, fa

Types of online analytical processing tools, Describe the various types of ...

Describe the various types of Online Analytical Processing (OLAP) tools and briefly discuss how the support common analytical operations.

Define functional and multivalued dependencies, Define functional and multi...

Define functional and multivalued dependencies.       Ans:  A functional dependency is a assets of the semantics of the attributes in a relation. The semantics point out how at

Define two-phase locking protocol, Define two-phase locking protocol. A...

Define two-phase locking protocol. Ans: Two-phase locking is significance in the context of ensuring that schedules are serializable. The two-phase locking protocol defines a p

What is a data warehouse, Problem 1 What is a Data Warehouse? Mention i...

Problem 1 What is a Data Warehouse? Mention its advantages 2 Explain the Top-Down and Bottom-up Data Warehouse development Methodologies 3 What is Data Transformation? Ex

Define object-oriented database, Question : Object-Oriented Database (O...

Question : Object-Oriented Database (OODM) is defined as a logical data model that captures the semantics of objects supported in object-oriented programming. An Object-Oriente

What are the key features of oracle, What are the key features of Oracle? ...

What are the key features of Oracle? Key features of Oracle are as follows: • Read Consistency • Concurrency • Locking Mechanisms • Quiesce Database • RAC • Portability

What are the functions of an accumulator, What are the functions of an accu...

What are the functions of an accumulator? The accumulator is the register associated with the ALU operations and sometimes I/O operations. It is an integral part of ALU. It hol

Correlated and uncorrelated queries, need to get answer for questions 3&4 o...

need to get answer for questions 3&4 on this page in part 1

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