Determine the strong and weak entity, Database Management System

Assignment Help:

Determine the Strong and Weak Entity

Based on the method of foreign key, there might be arise a situation when we have to relate an entity having a primary key of its own and an entity not having a primary key of its own. In such a case, the entity having its own primary key is known as a strong entity and the entity not having its own primary key is known as a weak entity. Whenever we need to relate a strong and a weak entity together, the ERD would alter just a little.

Say, for instance, we have a statement "A Student lives in a Home." STUDENT is obviously a strong entity having a primary key Roll. But HOME might not have a unique primary key, as its only attribute Address may be shared by a lot of homes (what if it is a housing estate?). HOME is a weak entity in this case.

 


Related Discussions:- Determine the strong and weak entity

What is online transaction processing, What is OLTP (Online Transaction Pro...

What is OLTP (Online Transaction Processing)? In OLTP - online transaction processing systems relational database design use the discipline of data modeling and generally follo

What is the meaning of data independence, What is the meaning of Data indep...

What is the meaning of Data independence? Data independence means a programs that are not dependent on the physical attributes of data and a programs that are not dependent on

Explain the disadvantages of using dbms, Explain the disadvantages of using...

Explain the disadvantages of using DBMS There could be a few disadvantages of using DBMS. As DBMS requires computers, we have to invest a good amount in acquiring the hardwa

Explain the concept of a data model, Explain the concept of a data model ? ...

Explain the concept of a data model ? Data Model - Model is an abstraction procedure which hides irrelevant details although highlighting details relevant to the application

Equijoin, When every condition appears with equality condition (=) only. c)...

When every condition appears with equality condition (=) only. c)   Natural join (denoted by R*S) When two join attributes have the similar name in both relations. (Tha

Examine about the behavioural diagrams, Examine about the Behavioural Diagr...

Examine about the Behavioural Diagrams  The main objective of behavioural diagrams is to visualize, specify, construct and document dynamic aspects of a system. The interactio

What are the two types of serializability, What are the two types of serial...

What are the two types of serializability? The two types of serializability is a)      Conflict serializability b)      View serializability

Differentiate between strict and rigorous two phase locking, Differentiate ...

Differentiate between strict two-phase and rigorous two-phase with conversion protocol Ans:  Strict two-phase locking holds all its exclusive that is write locks until commit t

What is abstraction, What is abstraction? Abstraction in the object ori...

What is abstraction? Abstraction in the object orientation is a idea that provide opportunity to express necessary properties of object without providing much details of the im

What is the highest normal form of the table - normalization, In problems 1...

In problems 1 - 4, you are given the columns of a table, and a set of functional dependencies.  Determine the normal form of this table.  Remember that the normal form is the HIGHE

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