Car Rental System ER Diagram | Entity Relationship Diagram

Car Rental Management System ER Diagram

The car rental management system ER diagram shows the relationships of the system’s entities that build its database design. ER diagram describes the logical structure of the system’s database or data storage. It is done by identifying the car rental management process entities, their properties, and the interactions between them.

The car rental management system database design is sketched out using ER (entity-relationship) diagram. This sketch becomes the actual basis of the system’s data storage that will serve as data destination and source.

ER Diagram for Car Rental System: Details

The table shows the overall description of the ER Diagram for Car Rental Management System. It has a complete overview of the project’s information.

Name:Car Rental Management System ER Diagram
Abstract:The car rental management system ER diagram depicts the relationship between various entities. It can be thought of as a blueprint for your system (project) structure. 
Diagram:ER Diagram is also known as Entity Relationship Diagram
Tools Used:Diagraming tools that provide ER diagram symbols.
Users:Rental Owner, System Admin, and Clients.
Car Rental System ER Diagram: Details

What is Car Rental Management System?

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Online vehicle rental software allows you to keep precise records of your whole fleet in one location, making day-to-day operations straightforward. Your business would be illegal if you didn’t keep proper documents, and no one could audit you. You wouldn’t be able to get insurance or anything else.

Customers can hire a vehicle through a car rental web-based system. This technology allows the company to make its services available to the general public via the internet while also keeping track of its performance.

Car rental companies usually work with people who need a short-term car, like people who don’t own a car, people who are traveling outside of their city, or people who have damaged or destroyed cars that need to be repaired or replaced.

Online Car Rental System Features

  • Car Rental Management – Car Rental Management is the main feature of this system wherein ER diagram contains the basic details of the system. Its information was composed of the transactions done by the customers, and the buses available for rental.
  • Customer Management – This feature plays a big role in the system because this gathers important information about the customers. This information was used to track their transactions and other important matters regarding with the system.
  • Manage Buses Information – Bus information management was important for the system because it serves as the basis of the customers as they avail of the rental offered by the system. This information was monitored to keep the customers updated.
  • Transaction and Rental Management – Its feature will store the rentals made by the customers as well as the date of the transaction. This will also save and update the accommodation based on the date requested by the customers.

What is an ER Diagram?

In DBMS, the ER Diagram of car rental management system is also known as the system’s database design. It is the graphical depiction of relationships between all the entities involved in the system. Its major components are Entities, Attributes, and Relationships.

To build and troubleshoot relational databases, the car rental system ER Diagram is used. It works best with DFD (Data Flow Diagram), which is responsible for data movement. Developing the database design for car rental system would be much easier with the help of ER diagram.

Importance of ER Diagram

The importance of ER diagram for car rental management system is to help in modeling its data storage or database. It is the basis of the project’s database foundation for construction. The car rental system entity-relationship diagram (ERD) also aids in defining the data types to be stored such as their attributes and characteristics.

All other real-world projects are presented with ER Diagrams (database designs). To display the details and attributes of a data store, the er diagram for car rental management system is used in conjunction with its data flow diagram. It visualizes how data is connected generically.

ERD (Entity-relationship diagram) is utilized in software engineering during the planning phase of software development. It aids in the identification of various system constituents and their interrelationships. Car Rental Management System ERD is also used as the foundation of the car rental system DFD (Dataflow Diagram).

ER Diagram for Online Car Rental System

ER Diagram of Car Rental System shows the system entity relationships in each entity and their supposed functions in each relationship.

ER Diagram for Car Rental Management System
ER Diagram for Car Rental Management System

Based on the image above, the Entity-Relationship (ER) Diagram for Car Rental System tables is composed of the following: admin, customer, ticket, bookings or reservations, transactions, and reports.

The tables are made to meet the required specification of the system and provide much more specific details of each entity within the system.

Car Rental Management System Database Design

This Car Rental system database design was made based on managing rental requirements. The system can encode customers’ requests regarding the Car Rental. The system admin can access the customers’ status and information, and handle and update the data in accord with rental as well as the transactions made by their customers.

The features included in the system’s ER diagram were the security and monitoring of the rental and customers’ records, transactions, and status. These features were also listed and recorded in reports that served as the history of transactions done in the system.

Car Rental Management System ER Diagram Tables

These tables below provide the complete database table details such as Field NameDescriptionsdata types, and character lengths. Each of these tables represents the characteristics and the attributes of data storage.

The field column presents the names of each database’s attributes, the description column gives the complete thought of each attribute, the type column is their data type and the length is for their character lengths.

Table Name: Customer

stud_ID (PK)Customer IDInt11
fnameCustomer First NameVarchar255
lnameCustomer Last NameVarchar255
genderCustomer GenderInt11
ageCustomer AgeInt11
contact_addContact AddressInt11
cust_emailCustomer EmailVarchar255
cust_passCustomer PasswordVarchar255
Table Name: Customer

Table Name: Admin

admin_ID (PK)Admin IDInt11
fnameAdmin First NameVarchar255
lnameAdmin Last NameVarchar255
genderAdmin GenderInt11
ageAdmin AgeInt11
contact_addContact AddressInt11
admin_emailAdmin EmailVarchar255
admin_passAdmin PasswordVarchar255
Table Name: Admin

Table Name: Cars

car_ID (PK)Car IDInt11
car_numberCar NumberInt11
car _modelCar ModelVarchar30
car_statusCar StatusVarchar30
rent_prizePrize RentVarchar30
driver_ID (FK)Driver IDInt11
Table Name: Cars

Table Name: Rentals

rental_ID (PK)Rental IDInt11
rental_numRental NumberInt11
date_rentRental DateDate
time_arriveTime of ArrivalTime
destinationDate of AccommodationVarchar30
date_returnReturning DateDate
Table Name: Rentals

Table Name: Transaction

trans_ID (PK)Transaction IDInt11
trans_nameTransaction NameVarchar30
rental_ID (FK)Rental IDInt11
car_ID (FK)Car IDInt11
cust_ID (FK)Customer IDInt11
admin_ID (FK)Admin ID Int11
trans_dateDate of TransactionDate
Table Name: Transaction

Table Name: Driver

driver_ID (PK)Driver IDInt11
driver_nameDriver TypeVarchar30
Table Name: Driver

Table Name: Reports

report_ID (PK)Report IDInt11
trans_ID (FK)Transaction IDInt11
rental_ID (FK)Rental IDInt11
report_date Report DateDate
Table Name: Reports

The tables given will be the basis for developers on how would they do the car rental management system database design. It has the complete description of the database and they will put this into the program or data storage the same as the names given to each of the tables. They will create a database with the attributes given as well as the value of each attribute.

Car Rental System ER Diagram [PDF]

The ER Diagram for Car Rental Management System in DBMS Pdf provides the information explaining the concepts of the project database. You may apply this information to your capstone project. You can also use it directly or modify its content depending on your project’s requirements.

How to create an Entity-Relationship (ER) Diagram

Time needed: 5 minutes.

Steps in building the ER Diagram for Car Rental Management System with Cardinality Ratio.

  • Step 1: Familiarize the ER Diagram (Entity Relationship Diagram) Symbols and Cardinality

    Entity Relationship Diagram – shows the structure of data types in a project. It uses symbols to clarify its parts and relationships. Their symbols and applications must be familiarized before you build the ER Diagram.

    ER Diagram Symbols:
    Field – are the parts of a table that define the entity’s characteristics. In the database that the ERD models, attributes are commonly thought of as rows.
    Keys – is a technique to categorize data qualities. It is used to organize ER diagrams and assist users in modeling their databases to ensure that they are efficient. This is also used to connect different tables in a database.
    – Primary Key: identifies a single entity instance which means a unique attribute or set of attributes.
    – Foreign Key: is produced when data attributes have one too many relationships with other entities.

    ER Diagram Cardinalities:
    The styling of a line and its termination demonstrates cardinality and ordinality.
    The greatest number of times an instance of one thing can be related to instances of another entity is referred to as cardinality.
    While Ordinality refers to the fewest number of times a single entity instance can be linked to another.

  • Step 2: Finalize the entities included

    Start designing your ER Diagram by finalizing the entities that must be included in your car rental management system. This entity is represented by a rectangle, and you’ll want to leave plenty of room for them in future phases so you may add them to your design.

    An entity set is a group of similar entities with shared properties. A table or a table’s attribute is an entity in a database management system. As a result, by depicting relationships between tables and their characteristics, an ER diagram displays the whole logical structure of a database.

  • Step 3: Add the attributes of each entity

    After finalizing the entities, think about the qualities you’ll need to characterize each entity. The details of the various entities outlined in a conceptual ER diagram are supplied as attributes. Characteristics of an entity, a many-to-many relationship, or a one-to-one relationship are all examples of attributes. Multivalued attributes can be assigned to several values.

    The entity’s attributes were represented by ovals and can be seen in the tables of the car rental management system er diagram. These attributes can be a primary key or a foreign key in the database design of the project. Yoy ER diagram design could also be converted to the database of the system by declaring your right entities and their attributes.

  • Step 4: Describe the relationships (cardinality) between entities and attributes

    To plot relationships between the ERD you will need the entities, their attributes, and relationships. You will base the data structure from the evaluated information to have the exact Entity Relationship Diagram.

    A relationship is an association that describes how two entities interact. At the connector’s endpoints, the cardinality is indicated by a crow’s foot. One-to-one, one-to-many, and many-to-many are the three most common cardinal relationships. It’s the maximum number of times an instance of one entity can be linked to instances of another entity.


ER (entity-relationship) diagram is only one of the diagrams used to design and develop the Car Rental System. Each of the diagrams you design and create will help you in presenting your ideas and impart your abilities.

Creating the ER diagram will help you perceive the back end of the software which will hold all the data that’ll enter and exit the system. To learn more about the ER Diagrams and more, check out the related and recommended articles below.

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