Why should you care?

Top sellers board showing two #1 stores then #3 (no #2) matches how sports rankings behave.

See it live — copy this example

Run in MySQL Workbench or the mysql CLI.

SELECT p.sku,
       SUM(oi.qty) AS units_sold,
       RANK() OVER (ORDER BY SUM(oi.qty) DESC) AS sales_rank
FROM order_items oi
JOIN products p ON p.product_id = oi.product_id
GROUP BY p.product_id, p.sku;

What happened?

• Products grouped by total qty sold.
• RANK orders by units; ties get same rank and gap follows.
• Different from ROW_NUMBER which breaks ties arbitrarily.

Practice next

1. Seed order_items so two SKUs tie qty.
2. Run query; observe shared rank and gap.
3. Swap RANK for ROW_NUMBER — compare tie handling.
4. RANK() OVER (PARTITION BY category ORDER BY SUM(qty) DESC) if category exists.
5. Filter WHERE sales_rank <= 10.

Remember

RANK allows ties and gaps. Good for public leaderboards. Pair with ORDER BY on metric DESC.

DataFlow bestseller board

Admin UI shows SKUs with tied ranks during flash sale.

Outcome: Merchants see fair tie display without fake ordering.