Learn SQL vs HelloSQL

Let Us SQL is a learn-anywhere app that takes you from zero to confident with SQL, the language behind every database. No prior coding experience needed — you'll learn by doing, one bite-sized lesson at a time, until reading and writing SQL feels like second nature. Best of all, everything is taught using PostgreSQL, one of the most widely used databases in the real world, so the skills you build here are skills you'll actually use. 85 LESSONS. 11 CHAPTERS. A CLEAR PATH FROM BEGINNER TO JOB-READY. We've laid out a complete, carefully sequenced curriculum: 11 chapters and 85 lessons in total. You'll start with your very first SELECT, then move on to filtering with WHERE, sorting with ORDER BY, working with text, date, and number functions, aggregating data with GROUP BY and HAVING, writing subqueries, combining tables with JOIN, handling transactions, and finally creating tables with primary and foreign keys. Each step builds naturally on the last — and a set of real-world practice exercises at the end ties everything together. LEARN BY DOING, NOT JUST READING Every lesson pairs plain-English explanations with real query examples and hands-on fill-in-the-blank exercises. The sample data is drawn from everyday scenarios — a zoo, restaurant reservations, an online store — so you always know why a query matters, not just how to type it. Answer a question and you'll see instantly whether you got it right, so nothing slips through the cracks. BUILD A HABIT THAT STICKS A progress bar shows how far you've come, and a daily streak counter keeps you coming back. Your progress is saved right on your device, so you can always pick up exactly where you left off. MADE FOR YOU IF YOU'RE… • Brand new to SQL and looking for a friendly place to start • Taking your first steps toward data analysis or engineering • Looking to learn in the small pockets of time throughout your day LITTLE THINGS YOU'LL LOVE • No sign-up required — just open it and start learning • Works offline, wherever you are • An AI helper on hand whenever a question comes up • Clean syntax highlighting and a simple, distraction-free design Start today and learn at your own pace. Let Us SQL makes mastering data feel easy.

SQL tends to make sense while you're reading about it, then fall apart the moment you try to write it yourself. HelloSQL is for the writing part. You read a problem, write a query, and run it. The results show up as a table, and if they're right, it's marked correct right away. Grading looks at what your query returns, not how it's written, so your query doesn't have to match ours. There are 120 exercises, and most of them look like everyday reporting tasks. For example: "List payments from largest to smallest. If two amounts are the same, put the older one first." The practice data is built around an online store's orders, employee attendance, and billing for a subscription service. What's free and what isn't The first 30 exercises are free, and you don't need an account. They cover SELECT, WHERE, ORDER BY, and LIMIT. The other 90 move on to aggregate functions, GROUP BY, HAVING, INNER JOIN, LEFT JOIN, CASE, subqueries, CTEs, and window functions. You unlock all of them with one in-app purchase. There's no subscription and nothing recurring. When you're stuck Each exercise has three hints, and you open them one at a time. The first gives you only the idea. If that's not enough, the second shows the shape of the query, and the third tells you which tables and columns to use. We set it up this way so you don't have to jump straight to the answer. There's also a sample solution with an explanation, and you can tap any underlined term in a problem to see what it means. Coming back to it Your drafts save automatically, so you can close the app halfway through a query and finish it later. Missed exercises and bookmarks are kept together so you can try them again. Anything you get wrong comes back the next day. Exercises you get right come back too, after 3 days, then a week, then 3 weeks. The editor suggests SQL keywords and column names as you type, and you can look at the tables and their data at any point. It works on iPhone and iPad, in light or dark mode. If you've gone through a course or a book and want to actually use what you learned, this is a good next step. It also works as a warm-up before a SQL test or a technical interview. Before you download • The practice data is set in Japan, so some names, places, and text values are in Japanese. A few exercises ask you to type Japanese text into your query, such as WHERE city = '東京'. The exercise shows you the exact text to use. • You can practice and check answers offline. You only need a connection to buy or restore the unlock. • There are no ads. Exercise 1 is a single line that pulls every customer's name. It's a good place to start.