Explain weak and strong entity type, Database Management System

Assignment Help:

Explain weak and strong entity type ?

Weak and Strong entity type: An entity set which does not have a primary key is referred to as a weak entity set. The existence of a weak entity set depends on the existence of a strong entity set; it must associate to the strong set via a on-to-many relationship set. A discriminator of a weak entity set is the set of attributes that distinguishes between all the entities of a weak entity set. The primary key of a weak entity set is formed by the primary key of the strong entity set on that the weak entity set is existence depends, plus the weak entity set's discriminator.


Related Discussions:- Explain weak and strong entity type

What are the objectives of object design, What are the Objectives of object...

What are the Objectives of object design After going through this unit, you could be able to: explain steps of object design; discuss algorithms that reduce costs;

Eliminate columns not dependent on key, Eliminate Columns Not Dependent On ...

Eliminate Columns Not Dependent On Key The Employee Relation satisfies - First normal form - As it has no repeating groups. Second normal form - As it do not have multi-a

Project, the of super market system done in database

the of super market system done in database

State the rearranging the execution order for efficiency, Define the step -...

Define the step - Rearranging the Execution Order for Efficiency As we know that algorithm and data structure are closely related to one another, but data structure is conside

Nested relational model, what is Nested relational model? Explain with exam...

what is Nested relational model? Explain with examples.

Online Bakery Data Base Project, How much would you charge to create a data...

How much would you charge to create a database encompassing an Online Bakery with all the elements below? I. Describe the application that you would like to design. This should

Give expression in tuple calculus and domain calculus, Consider the subsequ...

Consider the subsequent relation schemes:  Project (Project#, Project_name, chief_architect)  Employee (Emp#, Empname)  Assigned_To (Project#, Emp#)  Give expression i

Select statement-data manipulation language, SELECT Statement This stat...

SELECT Statement This statement is used for retrieving information from the databases. It can be coupled with many clauses. Let us talk about these clauses in more detail:

What is rigorous two phase locking protocol, Differentiate strict two phase...

Differentiate strict two phase locking protocol and rigorous two phase locking protocol. In strict two phase locking protocol all exclusive mode locks taken by a transaction is

Why were functional methods fashionable in early days, Why were functional ...

Why were functional methods fashionable in early days? These are inspired directly by computer architecture and thus popular among computer scientist in early days. The divisio

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