Nervous About Your SQL Interview? Anxiety Ends Here.

Master SQL Interview Skills in WEEKS

Learn or refresh SQL skills by solving 80 coding interview questions. Video course, mentoring service available for purchase.

Or SELECT a Coding Question by Topic

To 🔥 celebrate the holiday season, Also check out our NEWLY launched Annual plan (Up to 50% off). Use coupon code THANKSGIVING15 and enjoy additional 15% off all paid plans. Coupon expires at 2020/11/30 .

Join us and

Land your dream data job

Significantly shorten the path to pursue your dream job as a data analytics professional!

200+

Students

3000+

Minutes

8000+

Solved

30+

Countries

Video course

Step by step solutions, tips and tricks to avoid common mistakes for your next data scientist SQL interview

1:1 Mentoring

Learn directly from people with multiple data scientist offers from FAANG companies.


Say goodbye to stress and nerves

Focus on things that matter

Become a confident candidate entering a SQL interview after practicing and solving 80 SQL problems.


Curated SQL interview problems

Online judge & immediate feedback

45 lectures

Online SQL Practice

A curated list of 80+ SQL interview questions. Practice anytime, all in a browser.

                            
/* 38. Most popular movie category */

SELECT
    C.category_id,
	MAX(C.name) AS name
FROM film_category FC
INNER JOIN category C
ON C.category_id = FC.category_id
GROUP BY C.category_id, C.name
ORDER BY COUNT(*) DESC
LIMIT 1;








            
                  
/* 54. High/medium/low customers */

SELECT customer_group, COUNT(*)
FROM (
	SELECT
		C.customer_id,
	    CASE WHEN SUM(P.amount) >= 150 THEN 'high'
	         WHEN SUM(P.amount) >= 100 THEN 'medium'
	         ELSE 'low' END customer_group
	FROM customer C
	LEFT JOIN payment P
	ON P.customer_id = C.customer_id
	GROUP BY C.customer_id
) X
GROUP BY customer_group;





                            
/* 61. Customer spend vs average customer spend */

WITH customer_ltd_spend AS (
SELECT
    P.customer_id,
    MAX(store_id) store_id,
    SUM(P.amount) ltd_spend
FROM payment P
INNER JOIN customer C
ON C.customer_id = P.customer_id
GROUP BY P.customer_id
)
SELECT
    customer_id,
    store_id,
    ltd_spend,
    AVG(ltd_spend) OVER(PARTITION BY store_id)
FROM customer_ltd_spend CLS
WHERE customer_id IN (1,100,101, 200, 201, 300,301, 400, 401, 500);

                            
/* 67. Quartile buckets by rentals */

WITH movie_rentals AS (
  SELECT
    F.film_id,
    COUNT(*) AS num_rentals,
    NTILE(4) OVER(ORDER BY COUNT(*)) AS quartile
  FROM rental R
  INNER JOIN inventory I
  ON I.inventory_id = R.inventory_id
  INNER JOIN film F
  ON F.film_id = I.film_id
  GROUP BY F.film_id
)
SELECT *
FROM movie_rentals
WHERE film_id IN (1,10,11,20,21,30);


                            

Don't just take our word for it, see what our customers are saying

💬 SQLPad is the best website I have used for practicing SQL. The databases and practice problems resemble real-world data and daily tasks in a data scientist / data analyst role. I landed a new job as a data scientist at a tech company after completing all the practice problems. I would definitely recommend SQLPad to all who would like to improve their SQL skills and prepare for technical interviews.


— William, Nov 2020

Data scientist, received a recent job offer

💬 SQLPad helped me to learn and practice for Software Engineer position interview. First I didn't create account, was solving and skipping the ones I could not solve but after interview I turned back to finish the rest and to get myself ready.


— Umedzhon, Nov 2020

Software engineer

💬 This course helped me get into a final round of a data scientist interview at Facebook. Didn't get an offer eventually because I didn't do well during the product sense round. However I got great feedback for my SQL interview session. Highly recommend this course to any fresh college graduates.


— Justin, Aug 2020

Data scientist candidate

💬 I am currently in question 30, I really like some of the questions you posted here. Also thank you for your excellent customer service !!!! Thanks 👋👋👋


— Mamath, Oct 2020

Data scientist candidate

⭐️⭐️⭐️⭐️⭐️

💬 Enjoying it so far, love the mix with practical exercises and the focus to land a job, that's really important because normal courses do not prepare you for interviews. Also, Leon is really kind and helpful.


— Jose, Sep 2020

Data scientist

💬 This site is a great resource for SQL interview practice questions. The interface is excellent! And even as someone who currently uses SQL for their day job, I have definitely improved my skills by working through these problems.


— Kyle, Aug 2020

Data scientist candidate

💬 Thanks for sqlpad. Really loving the experience. As someone transitioning into a data analyst position this is a great resource. Looking forward to your mentorship program.


— Su, June 2020

Transitioning into data analyst

💬 Just finished 80 exercises together with the cracking the SQL interview course. It covered every little details for data analytics professional's SQL interview. Thanks again Leon! Great stuff!


— Cecil, June 2020

Product analyst

⭐️⭐️⭐️⭐️⭐️

💬 Great course on SQL. Very comprehensive. All the SQL material I've pales compared to this.


— Len, Sep 2020

Fresh Data Science Graduate

Pick your perfect plan

Save up to 50% off on annual plans, billed annually

FREE

0

Limited access

  • Practice 5 QUESTIONS a day
  • Progress tracking
  • Solutions for FIRST 10 questions
  • 30 days money back policy
  • Private Slack community
  • 21 Video lectures
  • Email support

BASIC

7.4

Practice all 80 questions

  • Practice all 80 interview questions
  • Progress tracking
  • Solutions for FIRST 10 questions
  • 30 days money back policy
  • Private Slack community
  • 21 Video lectures
  • Email support

PROFESSIONAL

17.4

All 80 questions and solutions

  • Practice all 80 interview questions
  • Progress tracking
  • Solutions for ALL 80 questions
  • 30 days money back policy
  • Private Slack community
  • 21 Video lectures
  • Email support

PREMIUM

25.0

Everything included

  • Practice all 80 interview questions
  • Progress tracking
  • Solutions for ALL 80 questions
  • 30 days money back policy
  • Private Slack community
  • 21 Video lectures
  • Email support

Billed monthly

FREE

0

Limited access

  • Practice 5 QUESTIONS a day
  • Progress tracking
  • Solutions for FIRST 10 questions
  • 30 days money back policy
  • Private Slack community
  • 21 Video lectures
  • Email support

BASIC

9.9

Practice all 80 questions

  • Practice all 80 interview questions
  • Progress tracking
  • Solutions for FIRST 10 questions
  • 30 days money back policy
  • Private Slack community
  • 21 Video lectures
  • Email support

PROFESSIONAL

29.0

All 80 questions and solutions

  • Practice all 80 interview questions
  • Progress tracking
  • Solutions for ALL 80 questions
  • 30 days money back policy
  • Private Slack community
  • 21 Video lectures
  • Email support

PREMIUM

49.0

Everything included

  • Practice all 80 interview questions
  • Progress tracking
  • Solutions for ALL 80 questions
  • 30 days money back policy
  • Private Slack community
  • 21 Video lectures
  • Email support

Every paid plan has 30 day money back policy. Payments are securely processed by Stripe, cancel at any time.

Commonly asked questions

Not sure if SQLPad is right for you? Wonder why you need to take the course?

Here are the answers to some of the most common questions we hear from our customers

Me ice climbing at Matanuska Glacier, Alaska, summer of 2019

My name is Leon, a senior data science and machine learning executive currently working at a top tech company in Silicon Valley.

I’ve been using SQL for over 10 years, and it is still my go to programming language to prepare data.

Before moving to Silicon Valley, I was a research scientist at Amazon where I worked on real time pricing optimization with a large scale machine learning system.

I recently launched Cracking the SQL Interview for Data Scientists course, and I need a platform for my students to easily follow the course and be able to practice SQL interview coding problems, and I can't find a solution online, so I created SQLPad.

The nice thing about sqlpad.io is that everything can be done in a browser, and my students don't have to waste hours to configure the database on their own computers.

I created both Fullstack Data Scientist School (datascientistschool.com) and sqlpad.io.

SQL is a must know programming language for any analytics track data scientists, it is the  lingra fraca  for processing and managing data in the industry. I’ve been using SQL for many years, and it is still my go to language to prepare and manage data.

However, it is not a strong-typed language, and there are many popular database systems with different syntaxes and built-in functions, it could be very confusing for first timers.

As a hiring manager or part of the hiring committee, I often ask a lot of SQL questions during a data scientist job interview, and to make sure the candidate will be hands-on at work.

However, in my 15 years career, I have met so many fresh college graduates or young professionals starting their job searches without a solid coding skills in SQL, and in the end, they didn’t get a job offer.

The SQL interview can have other names or formats such as Technical Analysis during a FAANG company interview, you might be asked to perform a series of SQL operations to extract data and insights, and answer follow up questions about their products.

(*) FAANG: facebook, amazon, apple, netflx and google

The Cracking SQL Interview course focuses mainly on improving a candidate's SQL interview skills, saving their time by concentrating on things that really matter.

We have seen satisfied customers ranging from fresh college STEM students searching their first industry jobs, and young professionals who want to switch their career track to work on data science.

SQLPad and the SQL interview course significantly improved their hands-on data processing capabilities, with laser focused learning materials, to help land their dream job offers.

Yep. Both tiers: SQLPad Pro account (excluding video course, $19/mon) and the Cracking SQL Interview course (40 lectures, 20 videos, $49/mon) come with a 30 day money back policy.

The 1:1 mentoring service refund is done case by case, and it is in compliance with teachable's coaching service agreement.

There is definitely a lot to prepare to land your first job, especially given the current COVID-19 situation, hiring managers receive a lot more applications from qualified candidates, and it pushes the hiring bar significantly higher than before.

If you are interested to know more about how to prepare a data scientist interview, I wrote a blog to explain different types of data scientists tracks.

And if you are interested in find a job search mentor to help you get started with a concrete plan. Feel free to hire me.

I designed and created those 80 SQL coding questions all by myself, and it took many long hours of hard work during nights and weekend, therefore you are not allowed to use any of those questions outside of this website, without my permission.

If you represent a company and are interested to acquire a license to use my interview problems for your hiring process, please feel free to contact me. .

Sure, I’d love to hear from you and I will respond within 24 hours. Just send me an email or connect with me on Twitter.

Start today

Practice makes dream offers

Complete 80 SQL interview questions, receive your dream data job offers