“Create an ERD crows foot template for Customer, Sales Order, Order Line, and Product. Include customer ID, email, and full name; order ID, customer ID, placed date, and status; line ID, order ID, product ID, quantity, and unit price; and product ID, SKU, product name, and list price, with Customer placing orders, orders containing lines, and products appearing on lines.”
Read the decisions behind it.
Order Line resolves the many-to-many relationship between orders and products.
Foreign keys make the ownership of orders and lines explicit.
Crow's-foot symbols show whether related records are optional or repeatable.
Unique email and SKU fields demonstrate common alternate-key constraints.
Use it to plan a relational database where entities, attributes, and cardinalities matter. Use a UML class diagram when behavior and application objects are more important than database constraints.
Other examples in this family.
Common questions
What is an ERD crows foot diagram?
It is an entity-relationship diagram that uses crow's-foot symbols to show one-to-many, optional, and mandatory relationships.
How do I make a crow's-foot ERD?
Define entities and keys, connect related entities, then set the cardinality and optionality that match the business rules.
How do I read crow's-foot notation?
The three-pronged foot means many, a bar means one, and a circle means optional or zero.
Is an ERD template different from an example?
A template is a reusable starting structure. An example represents a finished schema for a particular application.
Do I need an account?
Yes, a free one. No card is asked for.