Step $2$: Design an Entity$-$Relationship Diagram $($ERD$)$

In this step, you will create an ERD to visualize the relationships between entities and ensure data integrity.

Instructions:

Define Relationships:

Use relationships to show how tables interact. For example:

$-$Users and Orders have a one$-$to$-$many relationship $($one user can have multiple orders$).$

Orders and Order Status may have a one$-$to$-$one or one$-$to$-$many relationship, depending on how you want to track the status history.

Specify Primary and Foreign Keys:

Make sure each table has a Primary Key $($PK$),$ and where necessary, add Foreign Keys $($FK$)$ to link entities.

For example:

$-$UserID in Orders is a foreign key linking to UserID in the Users table.

OrderID in Order Status links to OrderID in Orders.

Show Cardinality:

Indicate the cardinality of relationships $($e$.$g$.,$ one$-$tomany, many$-$to$-$one$)$ to clarify data structure and flow.

For example, a one$-$to$-$many relationship could be drawn between Orders and Menu Items if an order can include multiple items.

Draw the ERD:

You can manually draw your diagram or use any software you want such as vision etc.

Clearly label each entity, attribute, and relationship in the ERD.

Outcome:

A complete ERD diagram that visualizes all entities, attributes, and relationships, clearly defining Primary Keys, Foreign Keys, and relationship cardinality.