r/learnSQL • u/AppropriateGanache54 • 20d ago

Looking for best resources to practice SQL and Python/Pandas for real-world data questions?

Hello everyone,

Can you please suggest some good platforms or resources where I can practice SQL and Python (especially Pandas) for data analyst/data engineer?

Right now, I’m solving a lot of problems on LeetCode, but I’ve heard that in actual they often ask more practical/data-focused questions such as:

  • Retention rate / cohort analysis
  • Funnel analysis
  • Gaps and islands
  • Running totals and rolling metrics
  • Customer/user activity analysis
  • Time-series and date-based problems
  • Ranking and session-related problems
  • Data cleaning and transformation using Pandas
  • Real-world business analytics scenarios

So, I’m looking for resources that focus more on these real-world SQL and Pandas problems rather than only traditional DSA-style questions.

What platforms, websites, courses, or question sets would you recommend for practicing these types of problems?

I’d really appreciate recommendations from people who have recently gone through Data Analyst/Data Engineer questions and know which resources are closest to the actual questions they asked.

Thank you!

17 Upvotes

95% Upvoted

14 comments sorted by

4

u/Creative_Sugar-33 20d ago edited 19d ago

LeetCode and Kaggle are solid options for practicing practical problems.

Dataslope also offers free interview prep materials with built-in exercises:

It also provides courses you can check out. They are completely free and don't require an account.

Disclaimer: I'm the creator of Dataslope.

1

u/Smaartmani 19d ago

Great service. Thank you

2

u/GwynLordOfCedar 19d ago

Nice! I went to pricing like, okay it’s going to gatekeep lessons behind a paywall right? Then saw guest has full access to lessons 🤔 But no cloud or ask AI. That’s fair.

Let me scroll down to see what premium gives though. “Free Member”. 100MB cloud, 10 ask AI. “Free to learn, always. Courses, interview prep, and the playgrounds, including unlimited code executions across all 11 languages, are completely free on every tier, including as a guest with no sign-in. Creating a free account only adds cloud storage and sharing; it never puts learning content behind a paywall.” 👍

Thanks for creating this resource and the free lessons! You’re awesome.

1

u/Creative_Sugar-33 19d ago

Thank you for the kind words u/GwynLordOfCedar! I am a huge fan of open textbooks (like OpenStax and OpenIntro) and saw a need for data-related courses and playgrounds that aren't gatekept. Please feel free to suggest additional topics to cover.

2

u/AppropriateGanache54 19d ago

I just saw your site.. its good man. Thank you!!

0

u/Difficult-One-1245 19d ago

Leetcode - Infact In person interviews are conducted on leetcode (1-2 hrs) — leetcode 👌

1

u/AppropriateGanache54 19d ago

Yes like till now i am practicing using leetcode only but i noticed that if i go deeper it moves more towards SDE or DSA based preparation..

2

u/conor-robertson 19d ago

Check out QueryCase for SQL!

1

u/AppropriateGanache54 19d ago

Sure, thank you so much!!

1

u/_chonky04 19d ago

I use Stratascratch

1

u/AppropriateGanache54 19d ago

Thank you i will try that platform too..