Describe entity referential integrity and integrity, Database Management System

Assignment Help:

Describe entity referential integrity and integrity. Give an example of each.

Entity Integrity Rule - If there is a attribute A of relation R is a prime attribute of R then A cannot accept null values.

Referential Integrity Rule - In referential integrity, it is ensured in which a value in which appears in one association for a given set of attributes also appears for a certain set of attributes in another relation.

For example:

286_Student details.png

Roll No is the primary key within the relation STUDENT and Roll No + Course is the primary key of the relation GRADE. (Entity Integrity)
Roll No in the relation GRADE (child table) is a foreign key, which is referenced from the relation STUDENT (parent table). (Referential Integrity).


Related Discussions:- Describe entity referential integrity and integrity

Student database, tell me the functionality,advantages and disadvantages of...

tell me the functionality,advantages and disadvantages of student database

Determine object representation, Determine object representation As a ...

Determine object representation As a designer, we must choose properly that when to use primitive types in representing objects and when to combine groups of related objects,

Where does view definition stored, Where does view definition stored? ...

Where does view definition stored? A view definition is permanently stored as part of the database.

Explain nested relations, Explain nested relations? Nested relations ...

Explain nested relations? Nested relations The assumption of INF is a natural one in the bank examples we have considered. However, not all applications are best modelled

Define the term e-government, Question: (a) Define the term e-Governme...

Question: (a) Define the term e-Government and briefly explain, using appropriate examples, the aspects it covers. (b) Give four reasons as to why a country should adopt e

Define query processing, Define Query Processing Query processing is th...

Define Query Processing Query processing is the process of selecting the best plan or strategy to be employed in responding to a database request. The plan is then executed to

Improved availability, Improved availability: The data in a distributed sys...

Improved availability: The data in a distributed system may be replicated so that it is at more than one site. Thus, the failure of a node or a communication link does not necessar

Objectives of database manangement system, OBJECTIVES After going thro...

OBJECTIVES After going through this unit you should be capable to: Explain the File Based system and its limitations; Explain the structure of DBMS; Explain the

Which model is used to store data in tree structures, 1. Which model is use...

1. Which model is used to store data in tree structures Ans: Hierarchical model is used to store data in tree structures

Nested query, what is correlation in nested query

what is correlation in nested query

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