alonardo/car-dealership-using-postgresql

Car Dealership using PostgreSQL

I created an Entity Relationship Diagram (ERD) and used PostgreSQL to create a database for a fake car dealership.

ERD Thought Process

I created 8 different tables. Here's my understanding of the relationship between each table:

Customer - Purchase_Invoice (and Purchase_History) - one to many

• A single customer can purchase many cars, but a car can't be purchased by many customers
• The same logic applies to the Purchase_History.

Customer - Service_Invoice - one to many

• A customer can purchase several services for their car, but only one service invoice can belong to one customer
• The same logic applies to the Service_History.

Sales_Staff- Purchase_Invoice - one to many

• A salesman can sell many cars but each invoice can only be sold by one salesman
• The same logic applies to the Purchase_History.

Mechanic_Staff- Service_Invoice - many to many

• Several mechanics can work on several different cars.
• The same logic applies to the Service_History.

Car_Inventory- Purchase_Invoice - one to one

• One car can only be purchased once and one invoice can only belong to one car.
• The same logic applies to the Purchase_History.

Car_Inventory- Service_Invoice - one to one

• One car can only have a single service invoice, and one invoice only belongs to one car.
• The same logic applies to the Service_History.

License

Please direct any questions or comments to Andre.