This ER diagram shows a simple online store system. One customer can place none or many orders. The customer can add one or many products to zero or many orders. They can apply a discount code (if available) to zero or one order.
Online store diagram code in Gleek
Customer
string Customer_id
string Name
int Email
Order
int Order_id
int Product
string Total
Product
int Order_id
int Product
string Total
DiscountCode
int DiscountCode_id
int Value
Customer {1}-places-{0..n} Order
Product {1..n}-is added to-{0..n} Order
DiscountCode {01}-applied to-{01} Order
About ER diagrams
We often make an entity-relationship (ER) diagram, ERD, or entity-relationship model, in the early stages of designing a database. An ERD is perfect for quickly sketching out the elements needed in the system. The ERD explains how the elements interact. ER diagrams can be shared with colleagues. Their simplicity makes them ideal even for non-technical stakeholders.
Similar ER diagram examples
Hospital management system entity-relationship diagram
Online shopping entity-relationship diagram
Banking system entity-relationship diagram
Travel management system Er diagram
College management system ER diagram
Inventory management system ER diagram (Chen notation)