SQLearn is a free site for learning SQL. This page explains what information the site keeps, where it goes, and how to get rid of it. It is written to be read, not skimmed past. If anything here is unclear, email us and we will answer plainly.
The short version
- You can use every lesson, quiz and the playground without an account. In that case nothing about you is stored on our servers except anonymous exercise results.
- If you sign in, we store your name, email address, avatar and your learning progress so it follows you between devices.
- Your profile and leaderboard position are public by default. You can make them private in settings.
- We do not run ads, do not sell data, and do not use tracking or analytics scripts.
- You can delete your account yourself, at any time, from the settings page. It removes everything.
What is stored in your browser
Your progress (XP, solved exercises, boss scores, badges, streak) is saved in your browser's local storage so it survives a page reload. So is which daily and community puzzles you have solved. This data never leaves your device unless you sign in.
The SQL you type runs inside your browser. Your queries are not sent to us or to anyone else. The practice database is loaded into memory and thrown away when you close the tab.
When you sign in, the session token that keeps you signed in is also stored in local storage. We do not set advertising or third-party cookies.
What is stored on our servers if you create an account
Accounts are handled by Supabase, a hosted Postgres and authentication service. Our database is hosted in Supabase's Sydney, Australia region.
When you sign in with GitHub or Google, we receive your name, email address, avatar picture and the username on that service. When you sign in with an email magic link, we receive only the email address. We use these to create your profile and to identify you when you come back. We do not receive or store your password for any service.
Once you have an account we store: your display name, username and avatar; a public or private flag; your progress (the same numbers that live in your browser); the XP you earn each day, for the weekly leaderboard; which daily challenges you have solved and how many tries it took; and any community puzzles you submit.
Exercise results, with or without an account
Each time an exercise, quiz question, daily challenge or community puzzle is checked, we record which item it was, whether the answer was correct, how many hints were used and the time. If you are signed in, this is linked to your account. If you are not, it is stored with no identifier at all: no IP address, no device ID, no cookie.
We use these results to find exercises that are confusing or too hard and to fix them. They are never shown to other users and are never used for advertising or profiling.
What other people can see
If your profile is public (the default), anyone can see your display name, username, avatar, XP, level, badges, boss battle results, how many daily challenges you have solved, and when you joined. This is what appears on your profile page and the leaderboard.
If you set your profile to private in settings, none of that is visible to anyone and you are left off the leaderboard. Your progress still syncs.
Your email address is never shown to other users, and there is no way for another user to look it up.
If you submit a community puzzle, its title, text, hint and solution are shown publicly once approved, together with your username as the author.
Third parties
- Supabase (supabase.com) stores account and progress data and handles sign-in. Their privacy policy applies to how they run their infrastructure.
- GitHub and Google act as sign-in providers if you choose them. They tell us who you are; we tell them nothing beyond the fact that you signed in to SQLearn.
- Google Fonts serves the site's typefaces. Loading them means your browser makes a request to Google's servers, which see your IP address, as with any web font.
- Buy Me a Coffee hosts the "Buy me a pizza" button image and handles donations on their own site. Clicking it takes you to their site under their terms.
That is the full list. There are no analytics, advertising, session-recording or social media scripts on the site.
How long we keep things
Account data is kept until you delete your account. Anonymous exercise results are kept indefinitely because they cannot be traced to anyone. Community puzzles you submitted stay published after you delete your account, credited to "anonymous", unless you ask us to remove them.
Deleting your data
Signed in, go to Settings and press "Delete account". It removes your account, profile, progress, XP history, daily results and the link between you and any exercise results, immediately and without asking us. Progress saved in your browser is untouched; clear your browser's site data to remove that too.
If you cannot sign in and want your data removed, email us from the address on the account and we will do it.
Your rights
Wherever you live, you can ask us what we hold about you, ask for a copy, ask for it to be corrected, or ask for it to be deleted. Most of that you can do yourself on the settings and profile pages. For anything else, email us. We do not charge for these requests and aim to answer within a couple of weeks.
If you are in the EU, UK or a similar jurisdiction, the legal basis for processing your account data is that it is necessary to provide the service you asked for. Anonymous exercise results are processed on the basis of our legitimate interest in improving the lessons.
Children
SQLearn is not directed at children under 13, and we do not knowingly create accounts for them. Lessons work without an account, so younger learners can use the site without giving us anything. If you believe a child has created an account, email us and we will delete it.
Changes to this policy
If we change what we collect or how we use it, we will update this page and the date at the top. For anything significant we will also say so on the home page for a while. Continuing to use the site after a change means you accept the updated policy.