Why should you care?

DataFlow shop module mirrors Flipkart basics — catalog browse, cart, pay, fulfill — all backed by relational integrity.

See it live — copy this example

Run in MySQL Workbench or the mysql CLI.

CREATE TABLE products (
  product_id INT UNSIGNED AUTO_INCREMENT PRIMARY KEY,
  sku VARCHAR(40) NOT NULL UNIQUE,
  price_inr DECIMAL(10,2) NOT NULL,
  stock_qty INT NOT NULL DEFAULT 0
);
CREATE TABLE order_items (
  line_id INT UNSIGNED AUTO_INCREMENT PRIMARY KEY,
  order_id INT UNSIGNED NOT NULL,
  product_id INT UNSIGNED NOT NULL,
  qty INT NOT NULL,
  unit_price_inr DECIMAL(10,2) NOT NULL
);
SELECT p.sku, SUM(oi.qty) AS units
FROM order_items oi JOIN products p ON p.product_id = oi.product_id
GROUP BY p.sku ORDER BY units DESC LIMIT 5;

What happened?

• Mini schema for catalog + lines.
• Bestseller query JOINs lines to products and aggregates qty.
• Checkout txn (earlier lesson) wraps stock decrement + order insert.

Practice next

1. Create tables in DataFlow ecommerce module.
2. Seed products and one order with lines.
3. Run bestseller SELECT.
4. Add categories table and JOIN for category bestsellers.
5. Soft-delete products with is_active flag.

Remember

Normalize catalog, orders, lines. Transactional checkout with stock lock. Aggregate queries power merchandising.

DataFlow mini Flipkart

Tutorial capstone builds checkout on this four-table core.

Outcome: Learners ship working store API.