What is Entity Relationship Diagram?

The users will need to eventually update the records to apply the rental end date and hours of service. Multiple users MIGHT have to access the database simultaneously, but not often. It needs to have measures in place to prevent mistyping of equipment makes or models or vendor names. I would assume a separate database for each would be necessary.

ER diagram for car rental system is a visual presentation of entities and relationships of car rental software database.You can edit this template and create your own diagram. Creately diagrams can be exported and added to Word, PPT (powerpoint), Excel, Visio or any other document.
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An entity relationship diagram gives a snapshot of how these entities relate to each other. You can use them to illustrate how data is structured in business processes, or to detail how data is stored within relational databases. ER diagrams don't necessarily show how data is manipulated, or the exact process it steps through, but how the data entities are structured and related to each other. Entities are the things we need to store data about. Relationships are sometimes referred to as cardinalities, which describes the interactions numerically - but let's simply call them relationships.

Conceptual Design vs Logical Design vs Physical Design ERD

Conceptual Design - Creating an Entity Relationship Diagram (ERD) and associated data dictionary to represent the reality and capture business data requirements

Logical Design - Transforming ERD to relational model: tables, keys (constraints), etc.

Physical Design - Creating the database and other supporting structures based on a specific DBMS

Summary: in this tutorial, we will introduce you to a PostgreSQL sample database that you can use for learning and practice PostgreSQL.

We will use the DVD rental database for demonstrating the features of PostgreSQL.

The DVD rental database represents the business processes of a DVD rental store. The DVD rental database has many objects including:

15 tables
1 trigger
7 views
8 functions
1 domain
13 sequences

DVD Rental ER Model

PostgreSQL Sample Database Tables

There are 15 tables in the DVD Rental database:

actor – stores actors data including first name and last name.
film – stores film data such as title, release year, length, rating, etc.
film_actor – stores the relationships between films and actors.
category – stores film’s categories data.
film_category- stores the relationships between films and categories.
store – contains the store data including manager staff and address.
inventory – stores inventory data.
rental – stores rental data.
payment – stores customer’s payments.
staff – stores staff data.
customer – stores customer data.
address – stores address data for staff and customers
city – stores city names.
country – stores country names.

Download PostgreSQL sample database

Car Rental Database Template Printable

You can download the PostgreSQL DVD Rental sample database via the following link:

Car Rental Template Free Download

The database file is in zipformat ( dvdrental.zip) so you need to extract it to dvdrental.tarbefore loading the sample database into the PostgreSQL database server.

Car Rental Database Template Download

Download printable ER diagram

Besides the sample database, we also provide you with a printable ER diagram in PDF format. You can download and print the ER diagram for reference while practicing with PostgreSQL.

Car Rental Database Template Example

This tutorial introduced you to a PostgreSQL sample database named DVD rental. We will use this database in our PostgreSQL tutorials so make sure that you have it on your server.