You made it to the final chapter. This is where everything comes together. No more theory. No more "this is how a JOIN works." You already know that. Now you prove it.
In this chapter, you will build a complete e-commerce database from scratch. Then you will attack it with 40+ SQL challenges — SELECT, JOIN, aggregates, window functions, subqueries, data validation, stored procedures. Each challenge has a full working solution. Each one teaches you something real.
We are building a mini e-commerce platform. Think Flipkart or Amazon — simplified to 6 tables. This schema covers every SQL concept you have learned.
| Table | Purpose | Key Columns |
|---|---|---|
| customers | Who is buying | customer_id, first_name, last_name, email, city, signup_date |
| products | What is for sale | product_id, product_name, category, price, stock_quantity |
| orders | Purchase transactions | order_id, customer_id, order_date, total_amount, status |
| order_items | Line items in each order | item_id, order_id, product_id, quantity, unit_price |
| payments | How orders were paid | payment_id, order_id, payment_date, amount, payment_method, payment_status |
| reviews | Customer feedback | review_id, product_id, customer_id, rating, review_text, review_date |
Golden rule for practice: Write every query yourself FIRST. Struggle for 5 minutes. Then look at the solution. The struggle is where learning happens. Copy-pasting solutions teaches you nothing.
Key Point: This capstone chapter has 40+ hands-on SQL challenges with full solutions. Build the schema, solve the problems, prepare for interviews — all in one place.
Key Point: This capstone chapter applies every SQL concept through 40+ hands-on challenges with a realistic e-commerce schema.