SQL Learning Guide
🗄️ The DataCareerPath SQL Guide
SQL is the single most important skill for a data analyst. Used in 95% of analyst job postings, it's the language databases speak — and the first thing you'll be tested on in every interview.
This page is your free SQL learning hub. Bookmark it.
SQL Learning Path
Follow this order. Don't skip ahead.
- Week 1: Foundations — SELECT, FROM, WHERE, ORDER BY, LIMIT. Get comfortable querying a single table.
- Week 2: Aggregations — GROUP BY, HAVING, COUNT, SUM, AVG, MIN, MAX. Learn to summarize data.
- Week 3: JOINs — INNER JOIN, LEFT JOIN, RIGHT JOIN, FULL OUTER JOIN. Connecting multiple tables is 50% of real analyst work.
- Week 4: Subqueries & CTEs — Write cleaner, more readable queries with WITH clauses.
- Week 5: Window Functions — ROW_NUMBER, RANK, LAG, LEAD, SUM OVER. This is what separates junior from senior analysts.
- Week 6: Real Projects — Analyse a real dataset end-to-end. Put it on GitHub. This is your portfolio.
Essential SQL Commands Quick Reference
| Command | Purpose | Example |
|---|---|---|
SELECT |
Choose columns | SELECT name, salary FROM employees |
WHERE |
Filter rows | WHERE salary > 60000 |
GROUP BY |
Aggregate by category | GROUP BY department |
JOIN |
Combine tables | INNER JOIN orders ON id = order.cid |
HAVING |
Filter after grouping | HAVING COUNT(*) > 5 |
ROW_NUMBER() |
Rank rows in a partition | OVER (PARTITION BY dept ORDER BY salary DESC) |
Free Practice Resources
- 💻 SQLZoo — Interactive SQL exercises, free
- 💻 Mode SQL Tutorial — Excellent for analysts, free
- 💻 W3Schools SQL — Quick reference, free
- 💻 LeetCode Database Problems — Interview-style SQL practice
Get the Full SQL Cheat Sheet
Our SQL Cheat Sheet covers every command, function, and pattern in one beautifully designed 4-page reference — dark and light mode versions included.