December 23, 2022
If you’ve got an upcoming SQL assessment in a few days (or maybe even in a few hours!) and are looking to cram for it, I’ve got the perfect last-minute SQL Interview study plan for you!
Before we dive into tips & tricks for cramming for SQL interview tests, I want to remind you of something: in the arc of a career, one passed (or failed!) SQL assessment isn’t going to make or break your Data Analyst or Data Science career. Believe me, I literally wrote the book on Data Science Interviews, and I’ve failed my share of SQL interview tests too. Failure is how we learn, and is a necessary step towards achieving SQL greatness!
So, take a deep breath, and relax – we’ll make the most of the few hours, days or weeks you have to study, and give your upcoming SQL test our best shot!
If you’ve only got a few hours to study for a SQL interview, and don’t know SQL already, start learning SQL basics with SQLBolt and cram as many lessons while praying to the god of your choice.
If you do know some SQL, skip the tutorials. Don’t focus on learning any more new SQL commands because you’ll only confuse yourself! Instead, the highest ROI on your time is reviewing the list of basic SQL commands used in interviews like:
You can also review common aggregate functions used in SQL interviews like:
Hopefully, you’ve seen most of these commands before, and with just a few hours you’ll be able to refresh yourself on the most common SQL commands used in SQL assessments.
Finally, if you have the time, try this easier Facebook/Meta SQL interview question to get a sense of how SQL assessments are formatted. If this problem is still too hard, don’t let it demoralize you or freak you out – just get back to reviewing the SQL commands you already know.
It’s not worth losing your confidence just a few hours before a SQL assessment. Plus, even an easy question at Meta isn't that easy (since Facebook has a high hiring bar). Just try your best, and know that I admire you for even trying – most people wouldn’t even bother studying with just a few hours to prepare for a SQL interview, so kudos for this valiant attempt!
If you’ve only got 24-hours to cram for your SQL interview, I’d review the basic SQL commands and aggregate functions listed in the earlier section. I think W3's SQL tutorial is a great reference resource to check your understanding.
In addition, I’d also review SQL joins since they are one of the most common concepts tested in SQL interviews. From my experience, the question “What are the 4 different types of SQL joins?” is the most common SQL phone-screen question that gets asked.
Finally, I’d also review the 6-step problem-solving framework for SQL interviews:
While you won’t become a SQL-interview genius overnight with this framework, it has some crucial tips which you can immediately implement for your upcoming SQL assessment tomorrow.
If you've got a few days to prepare for a SQL test, you should cram by:
I’d read the entirety of the ultimate SQL interview guide for Data Analysts and Data Scientists. At 6,000 words, it’s the most-comprehensive free resource covering the most important topics to know for SQL interviews, and provides a great overview of what to expect.
The guide covers:
More importantly, the guide has several real SQL interview exercises (with solutions) from Tesla, Microsoft, TikTok, and Uber. While you can find a big list of 100+ SQL interview questions, for last-minute SQL cramming it can be overwhelming to know where to start with such a long question list. Because the guide curates just a few of the most-representative SQL interview questions, it’s a great place to start when you're short on time.
Now that you know how SQL interview assessments are structured, it’s time to seriously brush-up on your SQL commands. Since we’re dedicating a full day to prep, you should make time to review advanced SQL concepts like the most common window functions such as:
Once you're refreshed, start to practice the easy SQL Interview Questions on DataLemur. There’s a difference between just reading about SQL interviews, and actually sitting down to practice and solve some SQL interview exercises, so all the brushing up on SQL commands isn’t going to mean shit if you don’t sit there and apply what you learned.
If possible, practice the questions for the company you specifically have an interview with. For example, if you've got an upcoming Data Analyst interview at Amazon, here's 6 real Amazon SQL Interview questions.
Based on day 2’s SQL interview practice, identify your weaknesses and gaps in knowledge. If you have none (seriously?!?! NONE?), skip to the medium SQL interview questions.
But If you're a normal person who does have some holes in your SQL knowledge, don’t try to plug every hole all at once. Pick low hanging fruit, like SQL joins or aggregate functions, and start practicing SQL interview questions on only those topics. For example, if you are constantly messing up on JOINS, filter the SQL questions on DataLemur to the easy level, and then apply the “SQL JOIN” tag so you can get laser-focused on your prep.
By focusing on a specific paint point can accelerate your prep, which is crucial if you’ve only got a few days to study!