Have you decided to up your tech skills in 2023 by learning SQL? Great choice. SQL is one of the most in-demand skills in the job market today. The good news is, you don't need to spend thousands of dollars on expensive courses to learn SQL.

There are so many free resources out there to help you on your journey to become an SQL master.

In this article, I'll share 11 of the best free SQL learning resources for 2023 so you can start querying databases and analyzing data in no time. Whether you prefer interactive courses, books, cheat sheets or video tutorials, you'll find helpful materials for your learning style.

By the end of this year, you'll be writing complex SQL statements and designing entire databases.

Let's dive in and get started. The future is data-driven, so learning SQL is a smart move. With hard work and the help of these excellent free resources, you'll get there.

SQLBolt

If you're looking for a free, interactive way to learn SQL, SQLBolt is a great resource. This handy site provides lessons and exercises to help you pick up SQL basics quickly.

You'll start with an overview of what SQL is and how it works. Then you'll dive into creating tables, inserting data, querying records, and more. Each lesson builds on the last in a straightforward way.

The interactive coding exercises let you write actual SQL statements and see the results instantly. You'll get real-world practice querying a sample database. Stuck on something? SQLBolt offers hints to point you in the right direction.

Whether you're a beginner wanting to learn SQL for a new job or a pro brushing up on skills, SQLBolt has what you need. In just a few hours, you can go from SQL newbie to querying with confidence. Why not check it out? Your database skills will thank you.

SQLZoo

If you want to get hands-on practice with SQL queries, SQLZoo is a great free resource. This interactive website has been around since 1999, allowing users to write and run SQL code against a live database.

You'll find SQLZoo offers tutorials and lessons for beginners on various SQL topics. Work through examples on SELECT statements, JOINs, aggregation, subqueries, and more. Each tutorial provides an editor to write your SQL code and see the actual results. This helps reinforce what you're learning by allowing you to experiment with different queries.

SQLZoo also has over 200 questions to test your skills. These range from basic queries to more advanced challenges involving multiple tables and complex logic. Don't worry if you get stuck, solutions and explanations are provided for each question.

Overall, SQLZoo is an excellent way to learn SQL for free in a practical, interactive environment. Whether you're just starting out or want to strengthen your skills, the lessons and challenges on SQLZoo will boost your confidence in writing queries.

Give this long-standing resource a try and start running SQL code today!

Stanford University's Databases: Relational Databases and SQL

Stanford University offers a free online course to learn SQL. The course provides a comprehensive introduction to SQL, the standard language for communicating with relational databases. You'll learn the basics of the relational model and database design along with SQL queries, data manipulation, and database administration.

The course covers basic SQL syntax, as well as more advanced topics like SQL injection prevention. You'll get hands-on practice with creating tables, inserting data, querying data, joining tables, grouping and aggregating data, updating data, deleting data, and managing database schemas. The course also touches on database design topics like normalization, denormalization, and database modeling.

Overall, this course is a great way for beginners to develop core skills in SQL that are useful for a wide range of jobs. The content is engaging but not too technical, with short video lectures and interactive coding exercises.

You can work through the materials at your own pace for free. If you get stuck, discuss concepts and ask questions with other learners in the course forum.

Upon completing the course, you'll have a solid foundation in SQL and relational databases that will benefit you for years to come.

SQL for Data Analysis - Udacity

Udacity offers a popular free course to learn SQL for data analysis. This course teaches you how to extract and analyze data using SQL. It covers SQL concepts and includes quizzes to practice your SQL skills.

This course is ideal if you have experience coding in languages like R or Python. You'll learn how to manipulate data with SQL and gain valuable data analysis skills. The course curriculum focuses on using SQL for data analysis and covers topics like:

• Filtering and sorting data
• Aggregate function
• Joins
• Subqueries
• Window functions
• And more

By the end of this course, you'll be able to query databases and use SQL for data analysis. This is a great intro course for aspiring data analysts and data scientists. The course is free to audit but you can also earn a Udacity certificate for a fee.

Mode Analytics SQL Tutorial

The Mode Analytics SQL Tutorial is a great free resource to sharpen your SQL skills.

Interactive Learning

Mode provides an interactive SQL editor and sample datasets to practice on. You can write and run queries to analyze everything from ecommerce data to public datasets on topics like education, healthcare, and transportation.

• Start with the basics, learning simple SELECT statements, aggregates like COUNT() and SUM(), and filtering with WHERE.
• Then move on to more advanced topics such as joining tables, window functions, and aggregating time series data.

Real-World Examples

The tutorials walk you through realistic examples and case studies to help build your intuition. You'll analyze customer churn, sales performance, and other practical business questions using SQL.

• The lessons give you a prompting question and have you figure out the SQL to solve it. You get instant feedback in the query editor so you can refine your skills.
• You'll even create visualizations from your SQL queries using Mode's built-in chart types like bar charts, line graphs, and heatmaps.

Overall, the Mode SQL Tutorial provides interactive, hands-on experience with realistic datasets and examples. In just a few hours, you can go from SQL novice to confidently writing complex queries to solve data problems. The skills you build will translate directly to many analytics and data roles.

W3Schools SQL Tutorial

W3Schools offers a great free SQL tutorial to get you started. Their tutorials are simple to follow and provide interactive SQL editors so you can practice as you learn.

The tutorial covers the basics of SQL including:

• Creating databases and tables
• Inserting, updating and deleting data
• Querying data with SELECT statements
• Using filters, sorting and joins
• Aggregate functions like COUNT, MAX, and AVG
• And more.

W3Schools keeps their tutorials up to date with the latest SQL standards. So whether you want to learn MySQL, SQL Server, Oracle or another flavor of SQL, their tutorial has you covered.

Once you've gone through their beginner and intermediate tutorials, check out their references on SQL functions, operators, and data types. W3Schools is a go-to resource for web developers, and their SQL tutorial is no exception.

SQLCourse.com

If you're looking for a simple yet effective way to learn SQL, check out SQLCourse.com. This free e-learning website offers interactive SQL tutorials for beginners.The lessons start from the basics - what is a database, what is SQL, how to create tables, etc. You then move on to more advanced topics like joins, indexes and stored procedures.

Each tutorial has examples you can run in the built-in sandbox database. This hands-on experience will reinforce what you're learning and allow you to experiment.You can go through the lessons at your own pace, and they build on each other in a logical progression.

By the end of the course, you'll have a solid foundation in SQL and be ready to start writing queries for your own projects. The site is mobile-friendly as well, so you can learn SQL on the go wherever you have an internet connection.

For a free resource, SQLCourse.com packs a lot of value.

SQL Notes for Professionals book

If you're looking for a handy reference guide to learn SQL, check out the free SQL Notes for Professionals book. This book provides a quick overview of SQL queries, Data Definition Language (DDL), Data Manipulation Language (DML), stored procedures, and more. It covers the basics of SQL syntax and how to use SQL to access and manipulate data in relational databases like MySQL, Postgres, Oracle, and SQL Server.

The book includes examples for each topic to help you learn by doing. It starts from the very basics, so it's suitable for beginners.

However, it also covers more advanced topics like set theory, subqueries, common table expressions (CTEs), window functions, and SQL injection. This resource gives you a broad overview of SQL so you'll have the foundations to start writing queries and building databases.

To access the book, simply visit books.goalkicker.com/SQLBook and download the free PDF.

"Learn SQL the Hard Way" by Zed Shaw

This free ebook is a great hands-on resource for learning SQL. In his signature straightforward style, Zed Shaw teaches you SQL by having you actually build a database and manipulate data. He walks you through installing SQL, creating tables, inserting rows, querying data, and more.

The book covers beginner and intermediate topics in SQL, from data types and constraints to joins, normalization, and transactions. Each chapter presents a concept, shows examples, and gives you exercises to complete that reinforce what you’ve learned. It may feel like the “hard way,” but actively doing the work yourself is the best way to really understand SQL.

This resource is ideal for those who prefer to learn by doing. You’ll get a solid foundation in SQL that will serve you well for years to come.

The book is available as a free PDF, ePub, and web version, so you can learn SQL the hard way wherever you like!

I go the ebook from FreeComputerBooks website.

"SQL Performance Explained" by Markus Winand

This free online ebook is a must-read if you want to optimize your SQL queries. As the title suggests, Markus Winand explains SQL performance in depth but in a very simple and easy-to-understand manner.

Through this book, you'll learn how databases work internally, how queries are executed, and what impacts performance. Most importantly, you'll discover many tips and tricks to speed up poorly performing queries. Things like using indexes properly, avoiding full table scans, reducing I/O, etc.

The best part is Markus uses lots of examples to illustrate each concept so you can easily follow along. This book covers performance topics for all major databases like MySQL, PostgreSQL, SQL Server, and Oracle.

So if you feel your SQL queries could use a performance boost, read this free ebook. You'll be writing faster queries in no time!

Read SQL Performance Explainer.

SQL for Web Nerds

If you're a web developer looking to pick up SQL, this free web resource is for you. It covers the essentials of SQL in a straightforward way. Through a series of articles, you'll learn how to create tables, insert and query data, join tables together, and more.

Visit SQL for Web Nerds.

Conclusion

There you have it, 11 of the best free resources for learning SQL online. With interactive courses, tutorials, and coding exercises, you have everything you need to go from SQL newbie to proficient in no time. Now it's up to you - dive in, start building your skills, and before you know it you'll be writing complex queries and designing robust databases.

You've got this! Keep practicing and don't get discouraged if you make mistakes. SQL is a highly useful skill, and with hard work and persistence, you'll get there.

Happy Learning.