Daily Angular vs SQLDOU

Master Angular with daily bite-sized lessons — no overwhelm, no long videos. Daily Angular teaches Angular, TypeScript and RxJS through short interactive lessons, multiple-choice quizzes and drag-and-drop code exercises. Inspired by Duolingo, it turns one of the most powerful frontend frameworks into a 5-minute daily habit. Whether you are learning your first framework or preparing for an interview, Daily Angular meets you where you are. THREE COURSES, 137 LESSONS • Angular — components, templates, data binding, directives, services, routing, forms, standalone components and signals • TypeScript — types, functions, interfaces, classes and generics, advanced types, async, modules, decorators and design patterns • RxJS — observables, creation, transformation, filtering, flattening, combination, subjects, error handling, and RxJS inside Angular HOW IT WORKS → Short lessons: each one takes under 5 minutes → Quizzes: multiple choice, with an explanation for every answer → Drag & drop: fill the blanks in real code → Section summaries: a cheat sheet when you finish a section → Streak system: build a daily habit and track your consistency → Progress map: see exactly where you are → Star ratings: earn 1–3 stars per lesson based on your score WHAT MAKES IT DIFFERENT • 137 lessons and more than 1,000 exercises, in English and Spanish • RxJS taught properly: switchMap, mergeMap, concatMap and exhaustMap, and when each one is the right answer • Modern Angular: standalone components, signals, and the @if and @for control flow • Interview-shaped questions, not only syntax drills FEATURES • Dark & light mode • Available in English and Spanish • Free to start — the first section of every course • Streak reminders so you never lose momentum Daily Angular is built for developers who want to learn Angular the right way — through practice, not passive watching. Download now and start your first lesson today. SUBSCRIPTION Daily Angular Premium is an auto-renewable subscription, available monthly or yearly. The exact price is shown in the app before you subscribe. Payment is charged to your Apple ID account at confirmation of purchase and renews automatically unless cancelled at least 24 hours before the end of the current period. You can manage or cancel your subscription in your Apple ID settings. Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ App Terms: https://modernfrontendarchitecture.com/apps/daily-angular/terms/ Privacy Policy: https://modernfrontendarchitecture.com/apps/daily-angular/privacy-policy/

SQLDOU is an educational app that visualizes SQL query execution plans with step by step animation. The third entry in the DOU series, following PAKEDOU (networking) and KURAUDOU (cloud). This time the theme is SQL. Enter a query and watch the execution plan generate automatically, then follow each row as it flows through filtering, sorting, joining and finally arrives at the result. WHAT YOU WILL LEARN • Full Scan vs Index Why scanning every row (full scan) is slow. See how much faster a B Tree index makes searches. Run the same SQL with both scan methods and compare speed in real time. • B Tree Index O(log n) Supports range queries such as greater than, less than, greater than or equal, less than or equal and equality. Watch the tree structure locate target rows efficiently through animation. • Hash Index O(1) Pro A high speed index specialized for equality searches. Experience the real execution time difference between Hash and B Tree. • WHERE and DISTINCT See each row pass or get skipped by the WHERE condition in real time with PASS or SKIP badges. Observe DISTINCT removing duplicates step by step. • JOIN Pro Visualize how rows from two tables are combined. See the batch process that waits for both sides before executing the join. • GROUP BY and ORDER BY Pro Watch aggregation such as COUNT, SUM, AVG, MAX and MIN and sorting such as ASC and DESC animate their internal processing. Observe how they buffer all rows before producing output. • Custom Quiz Mode v3.0 Pro Define your own table name, columns and rows, write any SQL you want, and save the quiz. Replay or edit later. Go beyond textbook examples and reproduce real world scenarios you care about. 20 MISSIONS Progress through 20 missions across 6 levels. • Level 1 SELECT and WHERE 5 missions SQL fundamentals • Level 2 Scan Methods 4 missions Full scan vs index speed comparison • Level 3 ORDER BY and DISTINCT 3 missions Pro • Level 4 GROUP BY 3 missions Pro • Level 5 JOIN 2 missions Pro • Level 6 Final Challenge 3 missions Index optimization Pro Each mission includes a prediction quiz. The Predict Execute Verify cycle encourages active learning. Star ratings up to three track your progress. EDUCATIONAL FEEDBACK • Auto comparison run the same SQL with full scan and index and see the speed difference automatically • Scan narration watch each row being checked in real time with PASS or SKIP verdict • Diagnostic comments context aware explanations Pro Why slow How to improve Background knowledge • Table data preview see actual data while making predictions FREE AND PRO Free • Level 1 and Level 2 missions total 9 missions • Basic diagnostics one line comment • B Tree index • Free mode Pro one time purchase • All 20 missions unlocked • Detailed diagnostics Why How to improve Background • Hash index support • Advanced SQL JOIN GROUP BY ORDER BY DISTINCT • Custom Quiz Mode build save and run your own quizzes • No ads WHO IS THIS FOR • Students and junior engineers learning SQL basics • Anyone who wants to intuitively understand why indexes are fast • Database beginners learning execution plans • Instructors looking for training supplements • Developers building a foundation in SQL performance tuning