Where Can I Find Free Online Data Sets to Practice SQL?

Diving into the world of SQL can be an exciting journey. But to truly master this language, you need to practice SQL regularly. In this article, we'll guide you through some free online data sets that will help you take your SQL practice to the next level. Let's get started!

You've successfully installed your chosen RDBMS and grasped the basics of SQL. So, what's the next step? Naturally, you're eager to apply and practice the SQL functions you've learned from our course. Perhaps you've even completed our SQL Practice Set course and are ready to take on more challenges. To truly immerse yourself in database work, you need—unsurprisingly—a database! But where can you source data for your SQL queries?

Fortunately, the Internet is a treasure trove of free data just waiting to be explored. The key is knowing where to look. I'll guide you to some of the most engaging datasets available online, perfect for enhancing your SQL practice.

Ready to dive in? Let's embark on this data discovery journey together, and supercharge your SQL practice.

Why Look for Data Sets?

That's where SQL, or Structured Query Language, comes into play. It's the lingua franca of data, the key that unlocks the door to data analysis.

If you're completely new to SQL, don't worry—we've got you covered. Before diving into these datasets, I recommend starting with our SQL Basics course. This course is designed for beginners and will teach you the basics of SQL, from simple queries to more complex operations. It's a great way to get your feet wet and build a strong foundation in SQL. Once you've mastered the basics, you'll be ready to tackle real-world data with confidence.

Let’s get back to practicing SQL. How do you do that without data? Sure, you could conjure up your own datasets, but wouldn't it be better to work with real-world data? You need data that's messy, complex, and unpredictable—just like the data you'll encounter in your career. That's why I've scoured the web for the best free online datasets for you to practice your SQL skills.

From government databases to movie ratings, these datasets span a wide range of industries and topics. They're not just a sandbox for you to play in—they're a launchpad for your journey into the world of SQL. So, roll up your sleeves, fire up your favorite SQL editor, and let's dive into the world of data together.

Why SQL Practice Is So Important

Practicing SQL is crucial for several reasons. First and foremost, SQL  is the standard language for dealing with data stored in relational databases. It's used by many organizations across various industries – from tech companies to government agencies – to handle, analyze, and manipulate their data. By practicing SQL, you're equipping yourself with a highly sought-after skill.

Second, practicing SQL allows you to gain hands-on experience with real-world data. Unlike theoretical learning, practical exercises give you a taste of the challenges you might face in a real job scenario. You'll encounter data that's messy, inconsistent, or missing—issues that you'll need to resolve to extract meaningful insights. This kind of practice helps you develop problem-solving skills and a deeper understanding of how databases work.

Finally, practicing SQL can open up new career opportunities. Whether you're aiming for a role as a data analyst, database administrator, or data engineer, SQL is often a key requirement. Even if you're not in a tech role, having SQL skills can be a significant advantage. Many roles in marketing, finance, and operations also deal with large amounts of data and require employees to have some level of SQL proficiency. By practicing SQL, you're not just learning a new skill—you're enhancing your employability and future-proofing your career.

Data Sets to Practice SQL

The key to effective learning is to work with diverse datasets. By exposing yourself to data from different domains, you'll not only learn how to write SQL queries, but you’ll also understand how data is structured across various fields.

That's why I created this list of free online datasets for you to practice with. Each one presents its own unique challenges and learning opportunities, helping you become a well-rounded SQL practitioner. So, without further ado, let's dive into these datasets and start practicing!

1. Google Trends

Google collects petabytes of data. Every click, every query entered into the search engine, everything is tracked and saved. So why not use this for your SQL practice? Google Trends is one of the largest public data sets available. They can be compiled and analyzed freely. The sheer volume of data from which you can choose is overwhelming!

Google allows you to use its browser data and analyze what people are searching for and when they do it most often. Sounds like something from one of Orwell's books? Let me just add that you can analyze almost every possible search query, keyword, and their history since 2004.

To keep all this under control, various filters and data breakdowns are available. Thanks to this feature, in a few minutes you can narrow down your search to, for example, specific locations, time, or nature of data.

Another interesting feature is the list of trends, i.e. the most popular terms currently searched on Google. You can also click on any of the examples suggested by Google. By writing this article, I learned that most of the searches related to Taylor Swift in the last 30 days were from Utah. I can't figure out why. Do you know? Write it in the comment section ….

The annual rankings are also great. Google shows five search terms in several categories. It is also worth checking out the possibilities of data visualization by Google. Be warned, though—looking through all of this is really addictive and time-consuming!

Each statement and each report can be conveniently downloaded with one click in the form of a CSV file. You can import them into your program and view them using SQL. The possibilities are limited only by your imagination and courage in entering words into the Google Trends search engine.

For your first try, I recommend entering the phrase "Learn SQL" in Google Trends. See for yourself: is what we write about on the blogs only an empty promise, or does the world really need people who know SQL? I’ll give you a hint—the trend is growing!

2. Data.gov

This is a gigantic – and more importantly, completely open and free – collection of over 250,000 data sets from the US government. The website offers a great search engine where you can define topics of interest, time intervals, tags, locations, and even the data file format or data type.

In just a few clicks, you can access information about your city's budget or the average academic performance of students from your alma mater. You can easily find what you need. Take some time to dig deeper. Most of the data is offered in the popular file formats like JSON or CSV.

A website like this is great– not only for SQL practice but also for democracy and transparency.

3. FiveThirtyEight

This is not just a collection of data sets. It's an ABC News' site with articles, ratings, and essays. You will also find a lot of data ready to be used in a SQL project.

Are you interested in politics? See data from the U.S. presidential polls. You have access to data from many American research firms and think tanks; you can calculate averages and track changes. Biden or Trump? Find out who has more support currently in your home state.

Each of the lists can be downloaded as a CSV file. Comfortable, interesting, and engaging. In addition to politics, you will also find a lot of information about sports (e.g. “The Pace Of Play Has Never Been Faster In The WNBA”), podcasts, and videos.

FiveThirtyEight is one of the best websites of this type on the Internet. Have you come across a better one? Let me know in the comments.

4. Kaggle

When you learn SQL and use it, you will have to get to know this service sooner or later. It is more than just a data set. Rather, it's a place where members of the data community come and publish their creations. You will find not only interesting data sets but also a whole lot of materials. All these can help you get better at understanding SQL and working with large databases.

Kaggle has a simple search engine, which makes it easy to find what you are looking for. You can also use the hints or see what is currently the most popular.

I am a sports fan, so I chose two databases for myself. The first is “international football results from 1872 to 2020.” It is a constantly updated database of results from over 40,000 international soccer matches. A huge dose of knowledge and historical statistics, with almost 150 years of soccer history, in one database. It has to be impressive, and it is! By practicing SQL on it, you can, for example, compare the results of your national team from specific years or against the results of your most hated rivals.

The second database I found here was the Lahman's Baseball Database. Remember the movie “Moneyball,” starring Brad Pitt? You can feel like the owner of a baseball team and complete your dream squad. Haven't seen Moneyball? Read my article “SQL, Databases, and Hollywood Movies.”

Lahman's Baseball Database contains the complete batting and pitching statistics from 1871 to 2019. In addition, you also have fielding statistics, standings, team stats, managerial records, post-season data, and much more. Sound cool? It’s because it is.

The Kaggle service also provides you with chances to win some pretty good prizes. You get them for participating in competitions by developing predictive/classification models and competing with others on their results.

5. IMDb Data Set

Do you like movies? Then you must be familiar with IMDb. It’s the world's largest online database on films, actors, directors, screenwriters, film agents, and other people associated with the industry.

IMDb (The Internet Movie DataBase) was established 30 years ago. Since then, a huge global community has been developing the website. The database currently has entries for over 6 million movies, with data on over 100 million related entities in total. The website owners allow you to download their collections freely for personal use; you can't use them commercially.

The data set is divided into smaller ones to make it easier. For example, you can download just information about movies in a given language or just about a specific director. It’s all up to your imagination. As an example, try to find out the following: in how many movie titles does the word "learning" appear? Are you able to find out?

6. Airbnb

Legend has it that Airbnb started from when its founders rented someone an air mattress in their living room. Since then, their business has grown. Now there are thousands of locations around the world. Their website allows people who have unused rooms or apartments to connect with travelers who need a place to stay for the night. The idea for this business is so simple that it’s hard to believe no one came up with it before.

Airbnb has a database of its locations. You can download and use it for practicing SQL. Download, for example, all the data on Florence in Tuscany, Italy. You can search all the properties for a good place to stay, analyze user ratings, and compare prices. Found your favorite? Then you already know where to stay when you go on a vacation there!

In addition to the property lists, you can also download data that you can use in a GIS project. You don't know what this is and you want to learn? I recommend a great PostGIS course on LearnSQL.com. PostGIS is a spatial extension of the PostgreSQL database. You will learn how PostGIS stores geographical data and how its basic geographical functions can be used in simple and complex SQL queries.

7. Earthdata

I saved something really interesting for the last. With this service, you will gain access to data from NASA. Okay, so you won't find out if a UFO actually landed in Roswell. But you can learn a lot about the earth's atmosphere, solar radiation, ocean currents, storms, and tectonic movements. You can watch everything live or analyze it as databases.

Earthdata is part of the Earth Science Data Systems Program. As a regular user, of course, you won't get access to all of NASA’s resources. But you will have access to petabytes of data collected by scientists around the world on an ongoing basis. Want to see how the Antarctic snow cover has changed over the past month? No problem. Perhaps you are more interested in massif movements in central Asia? Or the air currents over New York? You can retrieve and process data, all while honing your SQL skills. You can also view data live on the site. The sky's the limit – pun fully intended!

Data Sets for SQL Practice

These are my picks for the cool data sets available online, perfect for honing your SQL skills. The digital world is teeming with similar resources, and your exploration is only limited by your available time and eagerness to dive into the world of data.

Remember, mastering SQL isn't a one-time event, but an ongoing journey. The key to becoming proficient is consistent SQL practice. Want more of that? Pick one of our hands-on SQL practice courses:

• SQL Practice Set - Refine your SQL skills with 88 interactive exercises, ranging from simple tasks with SELECT FROM statements to more advanced problems involving multiple subqueries.
• SQL JOINs - Review and deepen your knowledge of SQL JOINs with 93 exercises. Practice common (and less common) ways of getting data from multiple tables.
• Basic SQL Practice: A Store - Are you looking for problems to help you practice what you've learned? Here are 169 interactive online exercises that will take your skills to the next level.
• SQL Practice: University - Here are 156 interactive online exercises to refresh your basic SQL skills.
• Basic SQL Practice: Run Track Through Queries! - Do you like both sports and learning? We have something for you. Here are 119 interactive online SQL exercises to help you practice your skills. Challenge yourself, solve problems, and win the race to SQL proficiency.
• Basic SQL Practice: Blog & Traffic Data - Master SQL with blog and web traffic data for a pet supply store. Dive into data analysis with these 141 interactive online exercises.
• Monthly SQL Practice - Each month, we offer a short practice course to help LearnSQL.com users quickly practice their skills. We’ve assembled some recent challenges in this course – great for some extra practice!

Regularly applying your skills on varied data sets not only reinforces what you've learned, it also helps you discover new techniques and approaches. The phrase "practice SQL" should become your mantra as you work to cement and expand your knowledge.

If you're just embarking on your SQL journey, our beginner-friendly course, SQL Basics, is an excellent starting point. This course is meticulously designed to provide you with all the foundational knowledge you need in an easily digestible format. You'll get plenty of opportunities to practice SQL, ensuring that the concepts you learn stick with you. And you don't have to install or set up anything on your device. Everything happens in your browser.

For those who already have a grasp on SQL basics and are looking to level up, our Advanced SQL track is the perfect next step. This course will take you deeper into the world of SQL, covering more complex concepts like CTEs and window functions. It's an excellent resource for those looking to practice SQL at a higher level.

So, whether you're a beginner or an experienced user looking to practice SQL, we've got you covered. Embark on your SQL practice journey today and unlock the full potential of data!