Master SQL with These 7 Practicing Platforms

Have you faced difficulties answering SQL questions in a data science interview? Don’t worry, you’re not the only one.

SQL proficiency is a must-have skill for all data-related positions, whether you’re a data analyst, scientist, engineer, or seeking another desired role. While SQL may seem simple to learn, acing an interview with it requires more than just knowing the syntax.

So, what’s the solution? The answer lies in deliberate practice. In this article, we present a list of platforms to help you sharpen your SQL skills and ace that interview.

Let’s get started!

1- HackerRank: A Hub for Sharpening Your Coding Skills

HackerRank is a one-stop-shop for enhancing your coding skills, from software engineering to data analytics. The platform offers an extensive collection of coding interview questions, with a special emphasis on SQL. The SQL practice suite on HackerRank boasts hundreds of questions for you to hone your skills.

You have the option to filter the questions based on their difficulty levels – easy, medium, or hard. Additionally, you can select questions based on your comfort level, from basic to advanced SQL topics. The topics available for practice include select queries, joins, and aggregations.

After you’ve put your skills to the test, you can take HackerRank’s Skills Certification Test to gauge your SQL expertise. These tests are timed, putting your problem-solving skills under pressure as you strive to answer SQL questions within the allotted time. Currently, HackerRank offers the following SQL assessments:

• SQL Basic – tests your understanding of simple queries, relationships, and aggregations.
• SQL Intermediate – examines your grasp of joins, unions, and subqueries.
• SQL Advanced – explores your mastery of query optimization, modeling, indexing, and window functions.

You can access all the practice questions and assessments with a free account on the platform.

2- Get your SQL Skills Sharp with SQLPad

SQLPad provides opportunities for you to hone your SQL skills through its diverse array of practice questions. These questions include:

• Basic SELECT queries utilizing the WHERE clause and GROUPBY
• Multi-table operations like JOINs and UNIONs
• Working with Window Functions

All the questions come with varying levels of difficulty to cater to all skill levels. Plus, SQLPad even provides industry-specific questions, such as those from fintech, education, and e-Commerce. Create a free account to get started and access a selection of the questions.

3- StrataScratch

StrataScratch is an ideal platform for those seeking to sharpen their SQL interview skills. With a vast collection of questions at your disposal, you can filter based on topics and difficulty levels, as well as company-specific questions.

The platform offers support for PostgreSQL, MySQL, and Microsoft SQL Server (in beta), with a coding workspace to work in. And, if you prefer using Python, StrataScratch lets you use the pandas library to solve questions.

With a free account, you can access up to 50 questions with solutions and practice over 500 SQL questions.

4- DataLemur:

DataLemur offers a carefully curated set of SQL interview questions, sourced from top tech companies such as LinkedIn, Tesla, Microsoft, and Walmart, among others.

The platform offers over 40 SQL interview questions on topics including conditional aggregation, string and window functions, and cumulative sums.

5- SQL Challenges on LeetCode

LeetCode is a platform that offers opportunities for users to hone their SQL skills. Its collection of SQL problems encompasses a broad range of topics and difficulties. You can easily filter through the questions by the company name, which are tagged as such. However, a limited number of questions are accessible with a free account.

6- Mode’s SQL Learning Journey

If you’re searching for a comprehensive platform to learn and practice SQL, Mode is a great option. Its structured and well-organized SQL tutorial is a standout feature, divided into three sections:

• Fundamentals of SQL
• Intermediate SQL including JOINs, UNIONs, and aggregate functions
• Advanced SQL topics like subqueries, string functions, window functions, and pivot tables.

Each lesson comes with a set of practice questions that can be solved directly within Mode’s SQL editor.

7- SQLZoo

Looking to advance your SQL skills? Check out SQLZoo! This platform is designed to help you learn and practice SQL, from the basics of SELECT statements to more complex concepts such as window functions. Each lesson includes short practice exercises, and a dedicated assessment section is available for more challenging SQL questions.

Final Thoughts

With so many options to choose from, finding the perfect platform to practice your SQL skills can be a challenge. Consider factors such as your current level of knowledge and available time for practice. If you’re preparing for an interview, it’s especially important to focus on interview questions and brush up on tricky concepts like window functions, subqueries, and common table expressions. To help with quick reference, be sure to bookmark this SQL cheat sheet. Happy coding!