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

Types of locks, Types of Locks There are two necessary types of locks: ...

Types of Locks There are two necessary types of locks: Binary lock : This locking mechanism has two states for to a data item: locked or unlocked Multiple-mode loc

What is database files , The database files accept the actual data and ...

The database files accept the actual data and are typically the biggest in size. Depending on their shape, the tables for all the user operation can go in one database file-but

What is serializability, What is serializability? Explain its types? Th...

What is serializability? Explain its types? The data base system must control concurrent implementation of transactions, to ensure that the data base state remains consistent.

Which method is used to key transformation, Which method is used to key tra...

Which method is used to key transformation ? A hash method is used to key transformation.

Oracle, List and explain the memory constructs of the Oracle 12c databases?...

List and explain the memory constructs of the Oracle 12c databases?

Differentiate between logical database design and physical, Differentiate b...

Differentiate between logical database design and physical database design. Show how this separation leads to data independence? Basis Logical Databas

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

Designing a Human Resources Database LASA1, Scenario: You are a freelance ...

Scenario: You are a freelance database designer who has just been contacted by a small software development company named Altair Software. The president of the company has asked

Relational database implementation, You must implement the entity relations...

You must implement the entity relationship model provided in the model solution to Assignment 1. The model solution will be released on the course website approximately TWO (2) we

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