SQL is one of the highest ROI skills you can learn — it's used by data analysts, backend engineers, product managers, and business teams everywhere. The good news: you can go from zero to job-ready in SQL without spending a cent. Here's the complete roadmap.
SELECT, FROM, WHERE, ORDER BY, LIMIT, DISTINCT, basic comparison operators (=, !=, <, >, BETWEEN, IN, LIKE, IS NULL).
Write 20+ SELECT queries against real tables. Use SQLab's schema browser to explore tables, then query them. Start with: SELECT * FROM users LIMIT 20; and work up from there.
GROUP BY, COUNT, SUM, AVG, MIN, MAX, HAVING, INNER JOIN, LEFT JOIN, multi-table JOINs, table aliases.
Complete all Easy and Medium challenges on SQLab. Aim to write at least one JOIN query per day.
Subqueries, CTEs (WITH clause), window functions (ROW_NUMBER, RANK, LAG, LEAD), CASE WHEN, string and date functions.
Complete all Hard challenges on SQLab. Study the solution after attempting each one yourself.
Find duplicates, Nth highest value, running totals, YoY growth, customer segmentation, self-joins for org charts, EXPLAIN query plans.
SQLab challenges (you're here!), SQLZoo, Mode Analytics SQL Tutorial, LeetCode Database problems, StrataScratch.
Run all the queries from this article in our free SQL playground.
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