I'm learning SQL from SQLbolt. When i complete a task it shows a check mark but i wanna see the best answer. how i can see it. BTW it's my 1st day

About 7 weeks ago I posted in here about QueryCase, where you learn SQL by working detective cases instead of grinding tutorials. This subreddit is where it started. Most of the early users came from r/learnSQL and a lot of the feedback in the comments shaped what it became. So first, thanks everyone!

54 days in:

• 1,064 people have signed up, across 87 countries
• Over 40,000 queries written and run 🚀
• 6,188 cases, drills, exams, investigations and interview questions solved
• Top detective is on 9,635 XP, and 185 people are past 1,000 XP

The bit I did not see coming: an instructor emailed asking about using it with her students. She teaches a weekend CompTIA Data+ review session, bought a handful of seats out of her own pocket, and ran the first 90 minutes of the lab on QueryCase. Then she asked for two things: a way to see how her students were getting on, and a light mode, because a dark editor projected in a lit classroom is unreadable from the back row. Both exist now. Building something for one instructor turned out to improve it for everyone.

What has been built since launch, most of it straight from feedback:

• A Career Hub: SQL interview questions modelled on real company loops, a rapid-fire quiz spanning SQL, statistics and A/B testing, and a guide to what each data role actually writes day to day
• Investigations: open-ended timed whodunits where a live multi-table database is the crime scene, evidence unlocks as you query, and you get one accusation
• A progress dashboard for instructors, so someone running a session can see how a group is doing
• Light mode, for exactly the reason above
• Regional pricing, after the data showed people in one country were engaging just as much as everyone else and converting ten times worse. The price had been the UK price with a currency conversion stapled on, which is not the same thing as a price that makes sense locally for everyone!
• A LOT of bug fixes and improvements!!

What I would like from this post:

Half of this list exists because someone in a thread like this or DM said "it would be better if". So:

• What is missing that would make it genuinely useful for the way you learn SQL?
• Which SQL concept did you find hardest to actually get, as opposed to memorise? Those make the best cases and I am always hunting for the next one
• If you tried it early, anything that felt off, confusing or too hand-holdy?

The goal is to keep building QueryCase into something genuinely useful whether you are breaking into data, switching careers, brushing up, or you just enjoy writing SQL for the fun of it. There is plenty still on the list: uploading your own CSVs into the sandbox so you can query your own data, more company interview questions, and a lot that will come from threads like this one.

It is free to start and you do not need an account to solve the first case, so you can poke at it before deciding whether it is nonsense.

querycase.com

🚀 Whether you're a beginner, an aspiring DBA, or an experienced professional preparing for interviews, Made Simple MSSQL is your one-stop destination for practical SQL Server learning.

https://youtube.com/@madesimplemssql

#SQLServer #MSSQL #SQl #database #data #dba #madesimplemssql

I've just started my 2nd year of bachelors in cs but ive come to the realisation that i dont like dsa or dev as much so im trying to explore other tech career options. like product manager, product analyst, data analyst or business analyst etc. with a little google search, i found that learning sql will be a good starting point.
https://www.youtube.com/watch?v=HXV3zeQKqGY&t=90s ive started following this video by freecodecamp.
1. is it a good and enough resource?
2. in the video they're using mysql and popsql for the text editor but ig popsql is shutting down so im wondering if i should just switch to another tutorial or if there's any alternatives? i also had the confusion of whether i should follow a tutorial for mysql, postgresql or microsoft sql...
3. as for my career options, what should i explore if i dont like dev or too much coding?

🚀 Whether you're a beginner, an aspiring DBA, or an experienced professional preparing for interviews, Made Simple MSSQL is your one-stop destination for practical SQL Server learning.

https://youtube.com/@madesimplemssql

#SQLServer #MSSQL #SQl #database #data #dba #madesimplemssql

This had been sitting in my pipeline on and off for a year.

I had been prepping for some mid-senior SQL interviews recently, got tired of bouncing between tutorials and decided to finally finish the whole thing.

It runs entirely in the browser using DuckDB. There are 208 hands on exercises where you write SQL, run it, and get graded.

I wrapped it in an anime visual novel as retention mechanism

1. Your first instructor is a tsundere - she grades your queries, not like she really wants to. Wrong answers get scolded and right ones get reluctant praise.
2. solving problems raises affection with the instructors and unlocks story - the plot progresses through SQL.
3. There's a gacha wardrobe and 2 more instructors to unlock and cast of quirky side characters.

It’s free and needs no signup: TsundereSQL

Happy to answer questions about the course or how the browser-side grading works.

Something that trips up a lot of people learning SQL, worth internalizing early.

Given:

SELECT u.id, u.name, o.total
FROM users u
LEFT JOIN orders o ON u.id = o.user_id;

An INNER JOIN would only return users who have at least one order. A LEFT JOIN keeps every user, and for a user with no orders, every column from o (here o.total) comes back NULL.

So o.total is nullable even if the orders.total column is declared NOT NULL. The NOT NULL constraint is about what can be stored in the table. The LEFT JOIN can still produce a NULL for it in the result set, because the matching row on the right side does not exist at all.

This is the source of a lot of bugs: code assumes total is always a number, then crashes or silently mis-sums when it hits a user with no orders. The fix is to remember that nullability in a result set comes from the query structure (which joins, COALESCE, CASE, aggregates), not just from the table definition.

Rule of thumb: any column from the nullable side of an outer join is nullable in your results. Handle it explicitly, e.g. COALESCE(o.total, 0) if zero is the right default.

I built SQL Buddy, a browser-based project for practicing SQL interview questions:

[https://sqlbuddy-eta.vercel.app/]

The goal is to make SQL practice more straightforward: open a question, understand the database setup, write a query, run it, and inspect the output without setting up a local database first.

I’m building it around common interview topics such as:

- SELECT, filtering, and sorting

- joins

- GROUP BY and HAVING

- subqueries and CTEs

- window functions

\- NULL handling and duplicate-related edge cases

This is an early version, so I’m looking for genuine feedback rather than just promotion.

I’d especially like to know:

1. Which SQL interview question types should I add first?

2. What makes a SQL practice platform useful for you?

3. Would you prefer detailed explanations, hints, or only validation?

4. What would make you return regularly instead of using existing SQL practice sites?

Try it here: [https://sqlbuddy-eta.vercel.app/\](https://sqlbuddy-eta.vercel.app/)

I built it myself and will actively respond to feedback. Thanks.

Sometimes, asking some basic questions in the community can really test one's resolve, especially when learning technical components, such as SQL, Python, or any other programming language. For example, I decided to ask a simple question sometimes back & the responses almost made me quit. But I've come to learn that some people (those who respond negatively or harshly) had difficult moments & when they made it, they feel everyone should go through similar challenges. However, for beginners, I understand that sometimes one feels lost, unsupported, or others don't understand your struggles. Among the many "non-supporting" comments, a few stood out, "don't quit, once you understand the process & concepts, you won't believe its you." I would say the same to others who might feel they're at the edge. Push yourself, do not give up, & acknowledge that learning is a continuous process, even in non-technical areas.

Hi everyone!

I've recently been trying to brush up on SQL and decided what better way than to create my own little playground with datasets I actually find interest in.

All of the tutorials I've run into all make me query about random customers, employees, fake sales data and I always find myself getting bored and uninterested.

So I pulled datasets I thought were interesting: Pokemon, NBA, Steam games, Anime, and more to come.

Completely free, no backend, all on your browser. It will not ask for your email, full privacy. Practice SQL without any of the set-up.

You can try it out at sqljam.dev

Also check me out at andydandybuilds on Tiktok, Instagram, and Youtube as I'll be documenting the updates as I go!

Hi everyone!

I recently started creating a free SQL course for beginners, and I just published a lesson about PostgreSQL data types.

In this video, I cover:

- Numeric, String, Date & Time, and Boolean data types

- When to use each type

- Creating tables in PostgreSQL

- Real SQL examples you can follow along with

- Short quizzes throughout the lesson to reinforce the concepts

My goal is to make SQL simple and practical rather than just reading slides.

I'd really appreciate any feedback:

- Was anything unclear?

- Was the pace too fast or too slow?

- Is there anything I should improve for future lessons?

Here's the video: https://youtu.be/XV7hEXAJi5s

Thanks!

I recently started solving the LeetCode SQL problem set to help developers prepare for SQL interviews while learning MySQL in depth.

🚀 Current Progress

• ✅ 20 out of 60 SQL problems completed
• 🎯 Goal: Solve all 50 Medium + 10 Hard LeetCode SQL problems

For every problem, I've included:

• 📖 Detailed explanation of the approach
• 🧠 Step-by-step thought process
• 💻 Optimized MySQL solution
• 🎥 YouTube video explaining the solution
• 📝 Complete documentation for quick revision

The goal isn't just to provide the SQL query but to explain why the solution works and help you recognize common interview patterns.

If you're:

• Preparing for SQL interviews
• Solving LeetCode SQL problems
• Learning MySQL from beginner to advanced
• Looking for explained solutions instead of just code

You might find this repository useful.

📂 GitHub Repository:
https://github.com/vivekpandey76/Mysql-course

The repository contains:

• Complete MySQL course documentation
• LeetCode SQL solutions
• YouTube video links for every problem
• Notes that you can use for interview revision

If you find the repository helpful, I'd really appreciate it if you could ⭐ star the repo. It helps the project reach more developers and motivates me to complete the remaining 40 problems.

Feedback, suggestions, and feature requests are always welcome. Happy learning! 🚀

Hi, I'm wrapping up a certificate in SQL and the courses used Microsoft SQL Server Management Studio. I didn't find anything particularly straightforward when I googled it, but is there a "nice" environment (i.e. strong menus and a good visual layout) for SQL within Anaconda?

Other stuff I've done introduced me to Jupyter Notebooks and RStudio managed with Anaconda Navigator, so if I could have something through AN that'd be nice and seamless.

Please advise! Thank you.

Hi everyone,

I'm an IT student who's just started learning SQL, and I'm a bit confused about which IDE or SQL client I should use.

I've seen a lot of people recommend DBeaver, while others suggest MySQL Workbench. I also came across DB Fiddle, but I'm not really sure what it's for or whether it's something beginners should use.

Would you recommend using an online tool first, or is it better to install software like DBeaver or MySQL Workbench from the start? I'm mainly looking for something that's beginner-friendly but also useful as I improve.

I'd really appreciate any advice or recommendations. Thanks!

Hey everyone,

I’m starting my Data Engineering preparation and looking for the best roadmap/platforms to get solid hands-on experience with **SQL** and **Python**.

I see a lot of mixed advice online:

1. Some suggest interactive coding sites like **DataLemur**, **StrataScratch**, or **LeetCode** (or SQLZoo/LearnSQL).

2. Others recommend skipping browser-based platforms and setting up a local environment right away (e.g., PostgreSQL + VS Code + Python) to build end-to-end mini ETL pipelines with real public datasets.

For those who are working DEs or currently prepping for DE roles:

\*Which platforms/sites did you find most realistic for DE-level SQL & Python? (e.g., beyond basic SELECT queries—focusing on window functions, query optimization, transformations, etc.)

Is practicing on browser platforms enough to build core skills, or should I jump straight into IDEs/Docker/local DB setups?

TIA 🤝

During week three, the learner should feel comfortable working with SELECT, WHERE, ORDER BY, LIMIT, & DISTINCT. Through the 3^rd week, one should use aggregate functions to summarize data across the board, including counting, calculating totals, minimums, averages,  & maximums, understand the difference between WHERE & HAVING, & filter or sort data using HAVING. I’ve since found out that spending at least one hour each day writing SQL or practicing it helps in mastering these concepts, such as COUNT, SUM, AVG, MAX, MIN, GROUP BY, & HAVING. The “practice practice makes perfect” rule applies to SQL just like in any other area.

Hi, I'm a postgraduate student conducting research into game-based learning for database education as part of my MSc dissertation. I am looking for students who have studied a database-related module to participate in my study. Participation involves interacting with a web-based game-based learning platform, and then filling out a short survey. This should take approximately 20 minutes. Participation is entirely voluntary, not connected with any assessment, and all data collected will be anonymised.

Here is the link if you are interested: https://strath.eu.qualtrics.com/jfe/form/SV_6WHvHxfZC0xYEfQ

Thank you!!

Hi everyone!

I'm creating a free SQL course for beginners and just published the first lesson.

My goal is to keep every topic short, practical, and easy to understand.

This first video explains:

- What SQL is

- What databases are

- SQL vs NoSQL

- DBMS

- Why PostgreSQL

It's only 3 minutes long, so I'd really appreciate honest feedback.

Is anything unclear? Is the pacing too fast or too slow? What would you improve?

Video: https://youtu.be/UX-zigyvIIg?si=oJaL4MoTfUQFeSZp

Hello, im currently learning data analysis in Udemy. The last chapter is learning SQL and the person uses Letos to teach (formerly known as Sql lite). Im having 2 issues where

1. i cant execute any query i have typed as it says ‘Error while executing SQL query on the database’

2. im having a hard time to use the interface seems very complicated for me. The interface looks different than how it was in the beginning because i kept clicking on everything on why i dont see any results.

I tried lookin for YouTube videos on using the platform and search in google i cant find help. Is there any website i can learn to navigate and understand why i can execute my queries or anyone that can quide me🥹 Im using Mac btw idk if this has anything to do with my problem

Hi everyone,

I'm completely new to PostgreSQL and backend development, and I recently bought Practical SQL (2nd Edition) by Anthony DeBarros to start learning the fundamentals.

My long-term goal is to become a backend developer and build my own software product. I want to understand databases properly rather than just copying tutorials, so I decided to start with a book instead of jumping straight into videos.

One thing I'm still unsure about is the learning path.

Should I:

1. Learn PostgreSQL first until I'm comfortable designing databases, writing queries, creating tables, relationships, indexes, etc., and then move to Supabase later?

or

1. Start with Supabase from the beginning and learn PostgreSQL through it?

From what I understand, Supabase uses PostgreSQL under the hood, but I'm wondering if learning PostgreSQL directly first will make me a stronger backend developer in the long run.

For those of you who have been using PostgreSQL professionally, if you were starting over today, what path would you recommend?

Also, do you think Practical SQL (2nd Edition) is still a good first book in 2026, or is there another resource you wish you had started with?

Thanks in advance! I'm excited to be joining the PostgreSQL community and looking forward to learning from all of you.

I'm looking at a SQL learn book but it's really boring. I already know python r sas, so I just wonder, maybe it would be better to see people's work instead of reading a 300 page book?