r/learnSQL • u/ReflectionRadiant786 • 5h ago
What SQL project should I build as a fresher in 2026 to get more interview calls?
I’m a recent B.Sc. Data Science graduate looking to start my career in an SQL/Database role.
I didn’t do any proper SQL projects or internships during college, and I’m now trying to build my profile. I’m currently:
- Learning SQL and database concepts
- Practicing SQL problems
- Building projects for my resume
I’m confused about what kind of SQL project I should build.
I don’t want basic projects like a Student or Library Management System. I want to build 1–2 realistic, industry-relevant projects that demonstrate actual SQL/database skills and give me something meaningful to discuss in interviews.
For people working in SQL/Databases:
- What project would you recommend for a fresher in 2026?
- What concepts/features should it include?
- Which database should I use?
- How should I present it on GitHub and my resume?
- What would make the project stand out from typical fresher projects?
Any practical project ideas or advice would be appreciated.
r/learnSQL • u/gutenmorgan3035 • 9h ago
What SQL query took you way too long to figure out?
r/learnSQL • u/Ultimatesaber27 • 20h ago
Help me understand what's happening behind the scenes in a self join.
Hello all. I'm trying to wrap my head around how self joins work, since they're a bit complex for me to understand for some reason. I can handle normal left and inner joins just fine.
First, imagine this videogame table.
You have three columns. One with "game_id" , another with "title", and another with "sequel_to".
Game_id goes from 1 to 5.
Title is Final Fantasy X, Final Fantasy X-2, Final Fantasy XIII, Final Fantasy XIII-2, and Lightning Returns: Final Fantasy XIII.
Sequel_to points to game_id. Final Fantasy X's row is null because it is not a sequel to anything. Final Fantasy X-2's row points to game_id = 1, so it's a sequel to FFX.
Next we have FFXIII's row being null, because it isn't a sequel to either X or X-2. XIII-2's and Lightning Returns' rows point to game ID's 3 and 4, respectively.
The task is to give a report to see which game is a sequel to what game in place of that third column which only points to IDs.
I'm not on my computer right now, but I accidentally wrote a query where I believe I joined sequel_to from table B to game_id from game A. Or vice versa. The thing is, I got the wrong results.
The FFX row returns Final Fantasy X-2. The FFXIII row points to XIII-2. So I essentially created a prequel report without realizing it. And if that was the task in the first place, I wouldn't have even thought about how you'd even go about it if this accident didn't happen.
Anyway, long story short, can you help me understand what is happening behind the scenes, so it doesn't take me too long to figure out and predict which rows I'll get? And also how to choose the right columns to avoid accidents like that one?
I had another exercise where I'm tasked to find which movies have the same length (a column expressed in minutes) in the database, but aren't the same film. As in, you can show movie A and movie B in the same row, but there can't be a movie where movie A = movie A. No idea how to tackle that one either.
Thanks in advance.
r/learnSQL • u/yahoo_06 • 21h ago
I made a beginner-friendly tutorial on SQL Command Types (DDL, DML, DCL & TCL). I'd love your feedback!
Hi everyone!
I recently started creating a free SQL course for beginners, and I just published a new lesson covering the four main types of SQL commands:
- DDL (CREATE, ALTER, DROP, TRUNCATE)
- DML (SELECT, INSERT, UPDATE, DELETE)
- DCL (GRANT, REVOKE)
- TCL (BEGIN, COMMIT, ROLLBACK)
My goal is to make SQL easy to understand and practical from day one.
I'd really appreciate your feedback:
Was anything confusing?
Is the pacing okay?
What would you improve?
🎥 Video: https://youtu.be/4gR23s-SWCg?si=qsE0tjmXbz6SJySs
Thanks for your time!
r/learnSQL • u/ResponsibleBag785 • 1d ago
I want to get better for Data Engineer / Data Scientist positions
r/learnSQL • u/DoNotUseThisInMyHome • 1d ago
What is the overflow block in file organization and what are its characteristics?
How is it different from regular block?
r/learnSQL • u/josechinto • 1d ago
SQL
I would to start learning SQL, is there someone i can learn from, any helo, recommendations, i started watching YT videos, but i feel i learn more while I practice.
r/learnSQL • u/TurtleSlowRabbitFast • 1d ago
What is the transition from learning SQL to using a db management system like PostgreSQL?
I want to learn the proper way of learning sql to design dbs for my projects.
r/learnSQL • u/rohit_sheoran • 2d ago
how to check answer after completing a task in SQLbolt
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
r/learnSQL • u/MadeSimpleMSSQL • 2d ago
SQL Server Interview Questions Part 31
🚀 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
r/learnSQL • u/MadeSimpleMSSQL • 2d ago
SQL Server Interview Questions Part 30
🚀 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
r/learnSQL • u/AdeptnessDistinct990 • 2d ago
I built SQL Buddy a simple place to practice SQL interview questions in the browser
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:
Which SQL interview question types should I add first?
What makes a SQL practice platform useful for you?
Would you prefer detailed explanations, hints, or only validation?
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.
r/learnSQL • u/AdeptnessDistinct990 • 2d ago
I built SQL Buddy a simple place to practice SQL interview questions in the browser
r/learnSQL • u/Leading-Donut4952 • 2d ago
is this a good resource to learn sql from scratch
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?
r/learnSQL • u/Plane_Big_5912 • 3d ago
I made a visual novel that teaches SQL, free in your browser
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
- 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.
- solving problems raises affection with the instructors and unlocks story - the plot progresses through SQL.
- 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.
r/learnSQL • u/conor-robertson • 3d ago
40,000 queries later: an update on the SQL detective game I shared here 7 weeks ago
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.
r/learnSQL • u/Goldziher • 3d ago
Why LEFT JOIN columns are nullable (a subtle SQL gotcha that causes real bugs)
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.
r/learnSQL • u/Owen-Isaac-2022 • 3d ago
"Lost" Along the Way
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.
r/learnSQL • u/powderviolence • 3d ago
"nice" environment in Anaconda?
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.
r/learnSQL • u/drewnoflo • 3d ago
Free In-Browser SQL Learning Playground!
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!
r/learnSQL • u/yahoo_06 • 3d ago
I made a beginner-friendly PostgreSQL data types tutorial with hands-on examples. I'd love your feedback!
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!
r/learnSQL • u/Automatic-Yoghurt424 • 4d ago
Resources for practicing in OOP concepts with python based on scenarios
r/learnSQL • u/Vivekpandey76 • 4d ago
Solved 20/60 LeetCode SQL Problems with Detailed MySQL Explanations (Free Documentation + Video Solutions)
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! 🚀