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

Create a company database, Company Database: a-)Here is the ER Model ...

Company Database: a-)Here is the ER Model b-)Here is the Relational Model:     IMPORTANT NOTICE FOR SOLUTION TYPE: ***THIS ASSIGNMENT WILL BE SOLVED BY THE

Cataloguing, differences between a classified catalog and a dictionary cata...

differences between a classified catalog and a dictionary catalog

What is a view, What is a view? How it is related to data independence? ...

What is a view? How it is related to data independence? A view might be thought of as a virtual table, that is, a table that does not really exist in its own right but is inste

Attributes and tuple, Before we talk about the relational model in more det...

Before we talk about the relational model in more detail, let us first define some very basic terms used in this model. Tuple Every row in a table shows a record and is cal

Determine the objectives of object oriented design, Determine the Objective...

Determine the Objectives of object oriented design provide an overview of object oriented design; partitioning system to subsystems; describe how a software desig

Data model in DBMS, how many types of data model in DBMS? explain data abst...

how many types of data model in DBMS? explain data abstraction with its different level

What are advantages of object-oriented programming paradigm, What is the ma...

What is the major advantage of object-oriented programming paradigm? The ability to modify the explanation of an object without affecting the rest of the system is the main adv

Managing databases, 10A.53 Code an Oracle Database trigger to enforce the...

10A.53 Code an Oracle Database trigger to enforce the constraint that an employee can never change his or her department. 10A.54 Code an Oracle Database trigger to allow the

What are the two types of errors, What are the two types of errors? The...

What are the two types of errors? The two types of errors are: a) Logical error b) System error

Illustrate package classes and associations into models, Package classes an...

Package classes and associations into models  Programs are made of separate physical units which could be edited, imported, complied or otherwise manipulated. The careful part

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