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

Design an algorithm to implement operations, Design an algorithm to impleme...

Design an algorithm to implement operations  Each and every operation specified in the functional model could be formulated as an algorithm. The algorithm indicates how operat

What is the use of union and intersection operation, What is the use of Uni...

What is the use of Union and intersection operation? Union: The result of this operation contains all tuples that are either in r1 or in r2 or in both r1 and r2.Duplicate tuple

What is the concurrency identification, Concurrency Identification Whi...

Concurrency Identification While designing analysis, model we map real world model into our analytical model. Real life objects are simultaneous in nature, but all the design

Selective replication-data replication, Selective replication: This is a c...

Selective replication: This is a combination of generating small fragments of relation and replicating them rather than a entire relation. The data should be fragmented on require

Explain the terms data warehousing and data mining, Question: i) Explai...

Question: i) Explain the terms data warehousing and data mining. ii) Discuss the importance of the following security principles that a digital firm should amongst others, n

Wound-wait scheme-deadlock prevention, " Wound-wait" scheme : It is based o...

" Wound-wait" scheme : It is based on a preemptive method. It is based on a simple rule:                   If Ti requests a database resource that is held by Tj

Describe entity referential integrity and integrity, Describe entity refere...

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

Development of large scale distributed real systems, Question: (a) What...

Question: (a) What are the challenges in the development of Large Scale Distributed Real Systems? (b) What is backward engineering and forward engineering in a design packa

Discuss the different layers of ansi sparc architecture, Q.1 Briefly discus...

Q.1 Briefly discuss the different layers of ANSI SPARC architecture. Ans: The three layers of ANSI SPARC architecture are like this: 1. Internal view is at the lowest leve

What are the acid properties?, Question 1 What are the advantages of DBMS ...

Question 1 What are the advantages of DBMS approach in managing data? Question 2 What are the services provided by a database system Question 3 List and briefly describe

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