Entity Relationship model case study

Case study

“Saboo-Car-Rental-Services” is a car rental showroom ,who want to automate their business.
They offer different types of cars on rent as small car,SUV,MUV.
Each type of car has the maximum seating available and the tariff per kilometer.
The management wants the system to show availability of the number of cars of each type for serving the inquiry.The system should have a provision for booking the car.
Before the booking is made ,the customer needs to provide personal information and driving license details.
Booking is typically stored as booking date,date of rent,duration in hours and type of vehicle.
Once the booking is done a unique booking number is provided to the customer for their reference which they need to produce at the time they come to collect the car.
A new transaction record is created for each booking after the car is returned,specifying the kilometers used and the amount to be paid ,date of payment.”


Entity Relationship diagram

Entity Relationship Diagram..all about Relationships

when we design Entity sets during database designs through Entity Relationship Diagram, there have to be  some kind of connections existing between them too. These connections are called “Relationships “derived from the real world term. A relationship can be classified according to the degree or connectivity. The following are the important points to remember about relationships in Entity Relationship diagrams

  • A relationship is an association between entity sets.
  • The entity sets that are involved in the relationship are also known as participants.
  • Relationships are named and the name is generally a verb.
  • Relationships are always two ways i.e. they operate in both the directions, so the N: 1 between Students and Teachers could also be thought of as a 1: N between Teachers and Students.


DBMS Introduction

Introduction to Database Management Systems

This video demonstrates the need of DBMS ,the problems in the file based systems and the advantages of Database Management System in today’s era.


A database management system (DBMS) is a computer software application that interacts with the user, other applications, and manage the organization and storage of data in database .

Some of the important Database Management Systems in use:-

Name of DBMS Full Name Company Name Year Introduced Latest version Query Language
IMS IBM Information Management System IBM 1966 IMS version 12 DL/I
IDMS Integrated Database Management System Cullinet, CA technologies 1983 CA IDMS/DB Version 18.0 SQL
MS-Access Microsoft Access Microsoft 1992 MS-Access 2013 SQL
SQL Server 2000 Structured Query Language Server Microsoft 2005 SQL Server 2012 T-SQL
Oracle Oracle Oracle 1978 Oracle 11g PL-SQL

Applications of DBMS

  • Railway reservation and ticketing.
  • Airlines booking.
  • Hotel reservation.
  • Movie ticket booking.
  • Retail store billing.
  • Salary processing.
  • Mobile address book.
  • Students mark sheet processing and printing.
  • News paper printing and publications.
  • Library Information System.


  • Data redundancy:
  • Data Inconsistency:
  • Data Integrity problems:
  • Data Access difficulty:
  • Data Isolation:
  • Concurrent Access anomalies:

Advantages of using DBMS

  1. It represents complex relationships among different data items:
  2. Enforces data integrity in a System:
  3. Keeps a tight control on data redundancy:
  4. Efficient data access:
  5. Maintains data dictionary:
  6. Provides different interfaces through which users can manipulate data: