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

Dirty reads-problems of concurrent transactions, Dirty Reads: T10 reads a ...

Dirty Reads: T10 reads a value which is updated by T9. This update has not been committed and T9 aborts. T9 T10 Value of x old value = 200

Determine the object-oriented design process, An object-oriented design pro...

An object-oriented design process  1. Define the context and modes 2. Designs the system architecture 3. Identifies the principal system objects 4. Identifies concurrency in

A b-tree of order how much children m has maximum, A B-tree of order how mu...

A B-tree of order how much children m has maximum ? m has maximum m mchildren in a B tree.

Physical model of traffic data management, After the completion of the logi...

After the completion of the logical model the physical model is to be made. The oracle 10 G will be used as a database server and all the tables with their column are created and i

Give some encryption techniques, Give some encryption techniques? A)  D...

Give some encryption techniques? A)  DES  B) AES  C) Public key encryption

When are they useful justify with an example, When are they useful? Justify...

When are they useful? Justify with an example. The temporary tables are commonly used to support specialized rollups or exact application processing needs. Unlike a permanent t

What are the comparison operator in sql, What are the comparison operator i...

What are the comparison operator in SQL?  Comparison operator in SQL are =, LIKE and BETWEEN

Illustrate how customer relationship is promoted, FitAll Ltd is a company t...

FitAll Ltd is a company that manufactures clothes. Its processes are manual and there are stand-alone Information Systems that aid to manage them. The Information Systems were purc

What is primary index, Primary Index In primary index, there is a one-t...

Primary Index In primary index, there is a one-to-one relationship among the entries in the index table and the records in the major table. Primary index can be of two types:

Describe the iterative and incremental life cycle, Describe the iterative a...

Describe the iterative and incremental life cycle For an iterative and incremental life cycle, two criteria are process and time. The main components of showing a project devel

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