E-Commerce Database

Introduction

An e-commerce DB is the canonical project to learn relational design — users, products, carts, orders, line items, payments, reviews. Every concept you've learned shows up.

Understanding the topic

Core concepts to understand:

• Users (auth + profile).
• Products + categories.
• Carts & cart items.
• Orders, order items, payments.
• Reviews and ratings.

Syntax reference

Visual workflow / architecture:

users ──▶ carts ──▶ cart_items ──▶ products
                                ▲
orders ──▶ order_items ─────────┘
   │
   ▼
payments

Real-world use

Shopify, Amazon and every Stripe Checkout integration use exactly this model — refined over years.

Best practices

• Money in NUMERIC.
• Index every FK.
• Soft-delete sensitive data; never hard-delete payments.

Hands-on exercise

Interview preparation — practice these questions:

• Q1. Sketch an e-commerce schema.
• Q2. Cart vs order — design choice.
• Q3. Refund modeling.
• Q4. Inventory consistency.
• Q5. Reporting tables you'd add.