Comparison

Data Engineer Exam Prep vs SQL Hero

Price, ratings, monetisation and update history for both apps, side by side โ€” with what reviewers say about each.

Head to head
About

Data Engineer Exam Prep

Features
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Study on your phone. Continue on desktop. Use your phone on the move and a tablet or desktop when you want more room to study. Connect the same StudyCert account to continue your learning in the app and on the desktop web. Prepare for Google Cloud Professional Data Engineer with 500 practice questions and 110 key terms. Study coverage ยท 5 areas โ€ข Designing data processing systems โ€ข Ingesting and processing the data โ€ข Storing the data โ€ข Preparing and using data for analysis โ€ข Maintaining and automating data workloads 1. Build your foundation with key terms Use flashcards to learn meanings, exam context and selection cues. Mark terms as known or not yet known, then revisit unstudied or unfamiliar cards. Edit card content to suit your learning and restore the original when needed. 2. Practice and understand each answer Study in 50-question sets, by domain or by difficulty. Work through single- and multiple-choice questions, then read the explanation for the answer and each option. Choose all, unfinished or wrong questions; shuffle questions and choices; use a study timer; and resume where you left off. From the results of domain study, continue with key terms and related questions in the next domain. 3. Review mistakes and uncertain concepts Choose recent errors, review marks or repeated mistakes on the Review screen and practice them again. Check accuracy by domain alongside the terms you know or still need to learn. The glossary report shows term-learning status and accuracy on related questions together. 4. Check your preparation with a mock exam Practice time management with 50 questions in 120 minutes. Change answers before submission, resume a saved exam and receive grading when time expires. Afterwards, see correct, wrong and unanswered counts, your score and domain results, then revisit mistakes. This practice feature uses the included questions and does not determine an official exam score or pass result. Tools that fit your study routine Optional audio study reads terms and meanings aloud. Choose whether to include exam context and selection cues, set repeats and pauses, and control playback with the mini player. A study calendar, learning streaks, weekly goals, reminders for unmet goals and light, dark or system themes support your routine. Learning records are managed for each supported language. Some features require paid access. Check the included features and price on the purchase screen. Purchase restoration is supported. This is an independent study aid, not an official, affiliated or endorsed app of any exam administrator or certification body. Exam names and trademarks belong to their respective owners.

About

SQL Hero

Features
Read full description

SQL Hero helps you learn practical SQL in a structured, mobile-friendly way. Work through guided lessons, interactive exercises, and realistic examples designed to strengthen your SQL thinking step by step. Practice core topics such as filtering, sorting, joins, aggregation, data updates, and database fundamentals in a format that is easy to follow on your phone. SQL Hero is designed for learners who want a clear learning path, plenty of practice, and a polished experience that makes SQL more approachable, interactive, and engaging. Features include: โ€ข Guided SQL lessons with structured progression โ€ข Interactive SQL practice built for mobile โ€ข Tappable SQL tokens and mobile-friendly question interactions โ€ข Section tests and progress tracking โ€ข Optional AI-assisted help and feedback for supported learning moments โ€ข Support for both new learners and learners refreshing existing skills โ€ข Available in English and Traditional Chinese today Unlike more traditional learning platforms that focus mainly on passive reading or video-based learning, SQL Hero is designed around active phone-first practice, faster iteration, and more interactive learning support. SQL Hero offers free learning features as well as optional paid features. Some content and features, including certain AI-assisted experiences, Pro and Premium plans, hearts, subscriptions, and lifetime access, require separate in-app purchases or subscriptions. Important notes for learners: โ€ข Learning stats and progress are currently saved locally on your phone. Uninstalling the app may reset your learning stats, and switching to another phone during your study journey is not recommended at this stage. โ€ข Social sign-in with Apple and Google is available, but we still plan to improve and polish this experience further in future updates. We plan to continue expanding SQL Hero with more languages, more chapters, and more additional-question content in future releases. For support, billing, privacy, or feedback questions, contact support@mail.mgsqlhero.com. Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

Screenshots

Data Engineer Exam Prep4 screens
SQL Hero4 screens

Verdict

The call

The clearest difference is ads: Data Engineer Exam Prep at none against SQL Hero's shown. Data Engineer Exam Prep also leads on update cadence (every 10 days vs every 5 weeks). SQL Hero's advantage is iOS requirement (13.0 vs 15.1). On price, in-app purchases and device support there is nothing between them.

Scored on Price ยท Rating ยท Positive reviews ยท Number of ratings ยท Update frequency ยท Ads ยท In-app purchases ยท Monetization ยท Best chart rank ยท Devices ยท Requires iOS

CostPrice ยท In-app purchases ยท Ads ยท Monetization

Both are free to download. Data Engineer Exam Prep sells 1 one-off in-app purchase and SQL Hero sells 10 in-app purchases, starting at $7.99 per month. Whichever you choose, the download price is not the number that matters.

UpkeepUpdate frequency

Data Engineer Exam Prep ships an update every 10 days, SQL Hero every 5 weeks. Both last shipped on October 28, 2026.

Scorecard3 real differences ยท 3 level
Data Engineer Exam Prep versus SQL Hero: the parameters behind the verdict, then further details
ParameterData Engineer Exam PrepSQL Hero
PriceFreeFree
Update frequencyEvery 10 days โ€” betterEvery 5 weeks
AdsNo โ€” betterYes
In-app purchasesYesYes
DevicesiPhone, iPad, iPod โ€” betteriPhone, iPod
Requires iOS15.113.0 โ€” better
Further details โ€” not scored
Size106 MB62 MB
Age rating4+4+
DeveloperCHOI SEONGMINZICHENG LIU

In-app purchases

1 purchases

Data Engineer Exam Prep

One-time1
  • Lifetime Access$4.99
10 purchases

SQL Hero

Subscriptions4
  • Premium Monthly$7.991 Month
  • Premium Quarterly$19.993 Months
  • Premium Semiannual$34.996 Months
Show 1 more
  • Premium Yearly$59.991 Year
One-time6
  • Starter Pack Hearts$0.99
  • Standard Pack Hearts$4.99
  • Value Pack Hearts$12.99
Show 3 more
  • Mega Pack Hearts$24.99
  • Pro Lifetime$89.99
  • Premium Lifetime$129.99

Questions

Is Data Engineer Exam Prep free?
Data Engineer Exam Prep is free to download, with in-app purchases available.
Is SQL Hero free?
SQL Hero is free to download, with in-app purchases available.
Do Data Engineer Exam Prep or SQL Hero have ads?
SQL Hero shows ads; Data Engineer Exam Prep does not.
Which is updated more often, Data Engineer Exam Prep or SQL Hero?
Data Engineer Exam Prep ships an update every 10 days, and SQL Hero every 5 weeks. Most recently, Data Engineer Exam Prep was updated on October 28, 2026 and SQL Hero on October 28, 2026.

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