What is E-R model, Database Management System

Assignment Help:

E-R Model

This data model is based on real world that consists of basic objects named entities and of relationship among these objects. Entities are illustrated in a database by a set of attributes. An Entity - Relationship model is an abstract way to define a database. It generally starts with a relational database, which loads data in tables. Some of the data in these tables point to data in other tables - for instance, your entry in the database would point to various entries for each of the phone numbers that are yours. The ER model would define that you are an entity, and each phone number is an entity, and the relationship between the phone numbers and you is 'has a phone number'. Diagrams prepared to design these relationships and entities are called E-R diagrams or entity-relationship diagrams.

 

955_ER Model.png


Related Discussions:- What is E-R model

Write a qbe query to display names of cs department, Consider a table stude...

Consider a table student (std_id, std_name, date_of_birth, percent_marks, dept_name). Write a QBE query to display names of Computer Science department students who have scored mo

Differance between ddl and sdl, Differance between DDL and SDL? DDL and...

Differance between DDL and SDL? DDL and SDL - The data definition language (DDL) is used through DBA and database designers to describe internal schema, conceptual schema, and

Write the sql queries using data manipulation language, Problem 1. Writ...

Problem 1. Write the SQL queries using Data Manipulation Language (DML) statements. Insert values into student table with field names using insert command Display the

Explain about foreign key, What is Foreign Key Foreign Key: Sometimes...

What is Foreign Key Foreign Key: Sometimes we may have to work with an attribute that does not have a primary key of its own. To recognize its rows, we have to use the primar

Data handling and research methods, Data Handling and Research Methods: ...

Data Handling and Research Methods: The dataset encompassing 130 participants contains several variables measuring detrimental health related behaviours referring to the use o

State the objectives-data source, You will be analysing a set of financial ...

You will be analysing a set of financial data of your choice. It is not necessary to collect any primary data of your own, and publicly available secondary data will be sufficient

DBMS , need a DBMS system on any data for assignment.

need a DBMS system on any data for assignment.

single products ordered, For Colorado customers calculate the number of si...

For Colorado customers calculate the number of single products ordered. If a product is purchased on multiple orders, it should be counted only single time. The result should conta

What count function return in sql, What Count function return in SQL? C...

What Count function return in SQL? Count function within SQL returns the number of values. (Count function counts all the not null values in the exact column. If we need to cou

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