SQL for Data Science

Most enterprise data lives in SQL databases. A data scientist writes SELECT, JOIN, GROUP BY and window functions daily.

Learn SQL well — it's not going away.

Example 1 (sql)

SELECT city, COUNT(*) AS orders, SUM(amount) AS revenue
FROM orders
WHERE order_date >= '2025-01-01'
GROUP BY city
ORDER BY revenue DESC;

Classic reporting query.

Example 2 (sql)

SELECT user_id, amount,
  RANK() OVER (PARTITION BY user_id ORDER BY amount DESC) AS r
FROM orders;

Window function.

Key points

💡 Note: Learning to READ someone else's 200-line SQL query is a superpower in a data team.