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

Determine the advantage of object-orientation, Determine the advantage of o...

Determine the advantage of object-orientation Finally, object-orientation has advantage of continuity throughout analysis, persistent representation and design implementation.

Implementing a data mining algorithm, i need to implememnt a treee based mi...

i need to implememnt a treee based mining algorithm. do you have an expert that can do that?

What are the advantages of object oriented databases, What are the advantag...

What are the advantages of object oriented databases in comparison with others? Why it is still not widely used? Object oriented designs are coherent, efficient and less prone

Dbms, Retrieve the S&S In-Chapter Database (in Microsoft Access format) fro...

Retrieve the S&S In-Chapter Database (in Microsoft Access format) from the text's Web site (or create the tables in Table 4-5 in a relational DBMS product). Write queries to answer

What is known as a search key, What is known as a search key? An attrib...

What is known as a search key? An attribute or set of attributes used to look up records in a file is known as a search key.

Short note on mid square method of hashing, Short Note on mid Square Method...

Short Note on mid Square Method of hashing? Mid square method of hashing: In the method midsquare hashing, the key is squared and the address selected from the center of the s

What are the responsibility of file manager, What are the responsibility of...

What are the responsibility of File manager? File Manager : Manager allocation of space on disk storage and the data structures used to represent within stored on disk. It is a

How can redundant associations be done, How can Redundant Associations be d...

How can Redundant Associations be done It can be done by asking questions: i)  Is there a specific arrangement of network which would optimize critical aspects of completed

Explain the exec statement in sql, Explain the EXEC statement in SQL  A...

Explain the EXEC statement in SQL  Ans: All statements which start with EXEC SQL are embedded SQL database statements. High level languages such as C can be employed to write a

Field, examples of fields in a database

examples of fields in a database

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