SQL Query Logic vs Learn Binary

SQL Query Logic is an independent study app for learners who want to understand how SQL queries work, not just memorize syntax. It is built for beginners, students, analysts, developers, and interview candidates who need structured practice across fundamentals, practical skills, common pitfalls, and advanced concepts. Practice through 160 focused questions, each with a clear explanation so you can learn from every answer. - FSRS spaced-repetition intervals to review at the right time - Weak-point heatmap to show topics that need attention - Daily challenge for steady practice - Mock exams for timed review - Offline practice for commutes, travel, or quiet study - No login required Use it to review SELECT logic, joins, grouping, filtering, NULL behavior, subqueries, set operations, and reasoning patterns that often cause mistakes. Independent study app for SQL Query Logic practice. Not affiliated with, endorsed by, or sponsored by any company, certification body, exam operator, or vendor. All trademarks belong to their respective owners. Practice offline, no login required.

Finally understand binary and hex — by doing, not memorising. Learn Binary turns number-base conversion into fast, satisfying drills. See a number, build the answer on a tappable bit row or a clean keypad, and get an instant verdict with the place-value breakdown behind it. It's built around how you actually learn: a level climb, an ~80% mastery gate, and a three-minute daily habit. WHAT'S INSIDE - The drill — convert decimal ⇄ binary ⇄ hex, both directions. Tap the bits or type the digits, confirm, and see exactly why the answer is what it is. - The nibble block — the standout: see how 0x61 = 0110 0001 = 97, with hex sat over colour-coded 4-bit nibbles. This is the trick that makes hex click. - A level climb — one level per bit, from the first switch up to the full byte (the 256 Club) and beyond. Clear a level test to unlock the next. - Two's-complement — read and write signed bytes, with the sign-bit reveal. - Bitwise ops — AND, OR and XOR, worked one column at a time. - Byte Speed Run — an optional 60-second timed challenge once you've earned it. - Daily goal + streak — a gentle habit, with a streak freeze so one missed day doesn't wipe your progress. - Explore — scrub a number and watch decimal, binary and hex move together. BUILT RIGHT - Fully offline — no account, no sign-up, no tracking required. - A clean, friendly light design in apricot and teal. Remove ads with a single one-time purchase — it removes the interstitial ads, and it's the only thing we'll ever ask you to buy.