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

Balance transfer, Scenario 1: Power goes out after the first instruction. ...

Scenario 1: Power goes out after the first instruction. What happens?

DBMS, what is specialization?

what is specialization?

Obtain the house numbers street wise from database, For the relations answe...

For the relations answer the following queries in SQL Street (name, location, city) House (number, street_name) Lives (name, house_number) (i) Obtain the names of persons who liv

Explain the object-oriented decomposition, Explain the Object-oriented deco...

Explain the Object-oriented decomposition Object-oriented decomposition targets at identifying individual sovereign objects that encapsulate both a state and certain behavio

What is data model, A Data Model in software engineering is an abstract...

A Data Model in software engineering is an abstract model that organizes and documents the business data for interaction between team members and is used as a plan for creating

Explain the utilities which help the dba to manage database, Explain the ut...

Explain the utilities which help the DBA to manage the database? Every DBA uses database utilities to maintain and control their databases. But there is a lot of confusion wit

Note gate, i want notes on this topic

i want notes on this topic

Cost of reading a file , A file of employee have 10,000 blocks on a cylinde...

A file of employee have 10,000 blocks on a cylinder of a disk with characteristics r=8ms and btt=0.6ms I want to know the cost of read inthe file under following conditions for a q

Define deadlock recovery measures, Define Deadlock recovery measures       ...

Define Deadlock recovery measures                   To recover from deadlock, the cycle in the wait-for-graph should be broken. The common technique of doing this is to rollbac

Object query language and odmg schema , (a)    Provide the description of t...

(a)    Provide the description of the following ODMG schema in the Object Definition Language (ODL). (b)   Based on the above object database, write the following queries i

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