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

Attributes, Attributes and its types explain?

Attributes and its types explain?

Insert into command, INSERT INTO command : Values can be inserted fo...

INSERT INTO command : Values can be inserted for all columns or for the selected columns Values can be given by sub query. In place of values parameter substitution

Determine advantages of merging an association into a class, What are the a...

What are the advantages and disadvantages of merging an association into a class?  Advantages: i)  Less number of tables ii) Faster performance due to the fewer tables

Explain about primary key, Explain about primary key Primary Key: It ...

Explain about primary key Primary Key: It is one of the candidate keys that are taken to be the recognizing key for the entire table. E.g. although there are two candidate ke

Give short note on the following terms- dirty pages and etl, Give short not...

Give short note on the following terms:Dirty pages and ETL a.) Dirty pages. These are buffer pages which comprise modifications which haven't been written to disk. b.

Database manager, Database Manager It is the interface among low-leve...

Database Manager It is the interface among low-level data, queries and application programs. Databases typically need a large amount of storage space. It is kept on disks, as

Data base design, how to design a bakery business in data base

how to design a bakery business in data base

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