Many-to-many relationship, Database Management System

Assignment Help:

For each m:n relationship type R, we make a new table (say S) to represent R. We also contain the primary key attributes of both the participating entity types as a foreign key attribute in S. Any easy attributes of the m:n relationship type (or easy components of a composite attribute) is also contain as attributes of S.

For example, the m: n relationship taught-by among entities COURSE and FACULTY should be shown as a new table.  The structure of the table will contain primary key of COURSE and primary key of FACULTY entities

A new table TAUGHT-BY will be created as: Primary key of TAUGHT-By table

 

ID

 

Course_ID

 

{Primary key of FACULTY table}

 

{Primary key of COURSE table}

 

 

Please note that since there are no attributes to this relationship, thus no other fields.


Related Discussions:- Many-to-many relationship

Functional dependency, Functional Dependency Consider a relation R that...

Functional Dependency Consider a relation R that has 2 attributes A and B. The attribute B of the relation is functionally dependent on the attribute A if and only if for every

Define hot backup, Hot Backup: Some sites cannot terminate the database wh...

Hot Backup: Some sites cannot terminate the database while creating a backup copy of the files. The cold backup is not a reliable option. So different kinds of backing up database

What is rdbms, What is RDBMS? Relational Data Base Management Systems (...

What is RDBMS? Relational Data Base Management Systems (RDBMS) are database management systems that maintain data records and indices in tables. Relationships may be formed and

Basic concept of data base management system, INTRODUCTION Databases a...

INTRODUCTION Databases and database systems have become an essential part of our daily life. We encounter many activities that involve some interaction with a database almost

What are domain constraints, What are domain constraints? A domain is a...

What are domain constraints? A domain is a set of values that might be assigned to an attribute .all values that appear in a column of a relation must be taken from the similar

Authorisation, Authorisation Authorisation is the culmination of the ad...

Authorisation Authorisation is the culmination of the administrative policies of the organisation.  As the name shows, authorisation is a set of rules that can be used to verif

What are the ways in which signal can be generated, What are the ways in wh...

What are the ways in which signal can be generated A signal might be generated in many ways such as a Signal is result of particular physical condition. Whenever a process writ

Outer join, Outer Join: The use of Outer Join is that it still joins those...

Outer Join: The use of Outer Join is that it still joins those tuples that do not have matching values in common columns are also contained in the result table. Outer join places

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