Entity identifier key attributes, Database Management System

Assignment Help:

An entity type usually has an attribute whose values are distinct for every individual entity in the collection. Such an attribute is known as a key attribute and its values can be used to recognize each entity uniquely.

Strong entity set: The entity types having a key attribute are known as strong entity types or regular entity types.

  • EXAMPLE: The Student entity has a key attribute RollNo which uniquely recognized it, hence is a strong entity.

Attributes

Let us first answer the question:

What is an attribute?

An attribute is a property used to define the specific feature of the entity. So to define an entity entirely, a set of attributes is used.

For example, a student entity may be defined by the student's name, address, age, course, etc.

An entity will have a value for every of its attributes. For example for a specific student the following values can be assigned:

RollNo: 1234

Name: Supriya

Age: 18

Address: B-4, Mayapuri, Delhi. Course: B.Sc. (H)


Related Discussions:- Entity identifier key attributes

Define mysql_fetch_object(), What are the differences among MySQL_fetch_arr...

What are the differences among MySQL_fetch_array(), MySQL_fetch_object(), MySQL_fetch_row()? Mysql_fetch_object returns the result from the database like objects while mysql

Produce a logical database design for pharma, Using a database design appro...

Using a database design approach of your choice, produce a logical design for Pharma. 1) Your answer must consist of ONE the following: An entity-relationship (ER) diagra

Increased parallelism-data replication, Increased parallelism : Since the r...

Increased parallelism : Since the replicated date has several copies a query can be distributed or can be answered from the smallest loaded site. Also, with more replicas you have

Improved availability, Improved availability: The data in a distributed sys...

Improved availability: The data in a distributed system may be replicated so that it is at more than one site. Thus, the failure of a node or a communication link does not necessar

Fragmentation-design of distributed databases, Fragmentation: It is defini...

Fragmentation: It is definite as partitioning of a relation into various fragments.Every fragment can be stored at a dissimilar site.

What is aggregate function, What is aggregate function? Briefly describe it...

What is aggregate function? Briefly describe it? Aggregate functions are functions that take a collection of values as input and return a one value. SQL offers 5 built-in aggre

Customer service, as a customer service employee, explain five measures you...

as a customer service employee, explain five measures you would recommend a displeased student to patronise a school canteen

Shadow copy, why shadow copy technique is used?

why shadow copy technique is used?

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

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