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

Fragmentation, let us consider a table having 2200 records and the fixed si...

let us consider a table having 2200 records and the fixed size of the table to be considered as 25.then how many numbers of table is requredto perform horizontal fragmentation

Database, 3. (10 points) Assume that you have been presented with the follo...

3. (10 points) Assume that you have been presented with the following relation for the Baxter Aviation database: Charters (Pilot#, Pilot name, Aircraft ID#, #seats, Village, Fligh

Physical location of record is determined by which formula, The physical lo...

The physical location of a record is determined by which mathematical formula that transforms a file key into a record location? The physical location of a record is determined

What is conceptual model, What is conceptual model ? A conceptual model...

What is conceptual model ? A conceptual model is a independent of both hardware and software.

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

Define the wait for graph, Define the Wait for graph Ans: The wait-for-...

Define the Wait for graph Ans: The wait-for-graph is a directed graph and consist of nodes and directed arcs; the nodes of the graph are active transactions. An arc of the grap

Draw the dependency diagram for the relation, Consider the subsequent relat...

Consider the subsequent relation   Professor (Pfcode, dept, head, time)   It is assumed that      (i) A professor can work in much more than one

Checkpoint, what is check point in database management system

what is check point in database management system

What are the uses of odbc, What are the uses of ODBC? Under what circumstan...

What are the uses of ODBC? Under what circumstances we use this technology? ODBC expose database capabilities within a standardized way to the application programmer by an ap

Describe the strategies adopted by the ministry of ict, Question 1: (a)...

Question 1: (a) Planning and management of ICT projects have a very poor record in developing countries. Briefly explain five critical success factors for correct implementa

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