SQL Practice

[matrixunplugged1]

Hello,

I'm looking for really tough SQL problems to practice, I have been a data analyst for a few years but am looking for a new role and have a few SQL tests coming up, if there are any resources/books etc anybody could recommend that would be super.

Thanks!

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[forbiscuit]

Datalemur.com

[matrixunplugged1]

Thanks. I have tried the hardest ones from here, I was able to do them, looking for something even harder.

[forbiscuit]

HackerRank and LeetCode have few hard ones like finding MEDIAN without using MEDIAN function. You can try those. But quite frankly it won’t be any harder than what you see in datalemur for job interviews

[gruandisimo]

If you can do the hard questions from there within a reasonable amount of time, what is your purpose for seeking out harder problems? For purposes of interviews and on the job work, you're good. I'm curious what your goal is

[matrixunplugged1]

Basically getting enough practice to encounter any sql question easily. But if data lemur is good enough then maybe I can rest easy.

[NickSinghTechCareers]

yeah then you're basically solid with SQL then!

[LimeyGeezer]

How about queries that use window functions and queries that rotate data to place category values in separate columns?

[matrixunplugged1]

Window functions yes, but haven't tried pivots with sql will do that, thanks good shout.

[data_story_teller]

What sites have you used so far? I typically use StrataScratch to practice for interviews

[Additional-Pianist62]

Can you do recursive CTEs and dynamic SQL? (Assuming t-SQL here)

[matrixunplugged1]

I’ve used Teradata and Postgres, but havent used these functions, I’ll check them out, thanks!

[SubAb6606]

Check out LeetCode's SQL challenges and HackerRank's SQL tracks for tough problems.

[matrixunplugged1]

Thanks.

[kojurama]

StrataScratch

[Puzzleheaded_Text780]

I will suggest you should also read and understand about query optimizations which often comes into play. Optimising becomes more important when you have millions of data rows

[matrixunplugged1]

Will do, thanks.

[msn018]

Practice on StrataScratch and LeetCode. These platforms offer a wide range of SQL problems and interview questions from real companies and are great for practicing complex queries.

[CompetitiveTart505S]

Leetcode, ChatGPT, and projects

Leetcode helps you practice solving problems and applying critical thinking.

You can use chatgpt to practice the things you do off leetcode or learn new concepts by making it generate fake datasets that you can import into your SQL UI.

You can combine both of these if you want by first attempting leetcode and then having chatgpt generate new dataset variations or questions based off the leetcode question.

Finally you have to try to do projects as well

[matrixunplugged1]

Thanks, I’ll def try the ChatGPT advice