Top 9 Websites to Hone Your SQL Skills Online

In this article, we’ll cover the top 9 websites for practicing SQL, offering platforms filled with data, examples, and guidance to make learning easy. As you’re likely aware, SQL (Structured Query Language) is a programming language used to interact with databases. It’s the standard for managing tables, and most databases support it. Additionally, SQL is one of the most sought-after skills in the tech industry, essential for data analysts, data scientists, and software engineers alike

Why Practice SQL?

Before diving into the platforms, it’s crucial to understand why practicing SQL is beneficial:

• Skill Enhancement: Proficiency in SQL is essential for data-centric roles. Regular practice improves your ability to manage and analyze data efficiently.
• Problem-Solving: SQL allows you to extract, transform, and manipulate data. Consistent practice hones your problem-solving abilities, preparing you to handle real-world data challenges.
• Career Growth: SQL skills are highly sought after in various professions. Whether aiming to be a data analyst, web developer, or database administrator, mastering SQL can give you a competitive advantage.

Top Platforms for Practicing SQL

To assist you in honing your SQL skills, I’ve put together a list of some of the best platforms that cater to different skill levels:

1. SQLZoo (Perfect for Beginners)
   Website: SQLZoo
   Skill Level: Beginner to Intermediate
   SQLZoo is a great place for beginners to start. It provides a structured series of interactive tutorials and exercises, allowing you to practice SQL queries directly in your web browser. The tutorials cover a variety of SQL topics, helping you progress at your own pace.

Example: SQLZoo offers a beginner’s tutorial titled “SELECT from WORLD,” where you can practice basic SQL SELECT statements by querying data about countries.

— Example SQL Query

sql

CopyEdit

SELECT name, price 

FROM company 

WHERE type = ‘mobile’; 

Noteworthy Features:

1. Interactive Learning: Learn by doing rather than just reading.
2. Progressive Difficulty: Covers both basic and more advanced SQL concepts.

Pros:

1. Ideal for Beginners: Great for newcomers to SQL.
2. Instant Feedback: You’ll immediately know if you’re on the right track.
3. Comprehensive: Provides a broad range of SQL topics to explore.

Cons:

1. No Real Databases: The platform doesn’t simulate real-world databases.
2. Less Practical: The experience might not reflect SQL’s application in real-world scenarios.
3. Codecademy (Great for Beginners)
   Website: Codecademy SQL Course
   Skill Level: Beginner
   Codecademy offers an engaging and interactive SQL course perfect for beginners. With hands-on coding exercises and immediate feedback, the platform allows you to practice SQL in a structured, step-by-step manner. Here’s an example of a beginner exercise:

Example: Practice retrieving specific data from a database, such as extracting information from a table called employees:

— Example SQL Query

sql

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SELECT fst_name, lst_name, title 

FROM empls 

WHERE dept = ‘sales’; 

Key Features:

• Interactive Practice: Learn SQL in a user-friendly online environment.
• Progress Tracking: The platform tracks your progress to ensure you’re on the right path.

Pros:

• Hands-On Learning: You learn by actively doing, not just listening.
• Easy to Follow: The course is designed to be simple to understand.
• Fun and Engaging: Codecademy makes learning enjoyable.

Cons:

• Not Suitable for Advanced Users: Experienced users may find the content too basic.
• Paid Content: Some advanced features require a paid subscription.

3.SQLFiddle (For Intermediate Users)
Website: SQLFiddle
Skill Level: Intermediate
SQLFiddle is an online platform that lets you write and run SQL queries across multiple database systems. It’s ideal for practicing SQL in a more realistic setting. Here’s an example of how you can use SQLFiddle:

Example: Experiment with different SQL databases like MySQL, PostgreSQL, or SQLite. You can create a table and insert data into it.

— Example SQL Query

sql

CopyEdit

CREATE TABLE studs ( 

    id INT AUTO_INCREMENT, 

    name VARCHAR(50), 

    age INT 

); 

INSERT INTO studs (name, age) 

VALUES (‘Dave’, 25), (‘Jane’, 28), (‘Gill’, 22); 

Notable Features:

2. Test Across Multiple Systems: Practice SQL on databases like MySQL, PostgreSQL, and more.
3. Real Database Feel: It simulates working with a real database.

Pros:

2. Experience with Real Systems: Learn how SQL behaves on different database platforms.
3. Collaboration: Share your SQL code with others and seek help if needed.
4. Instant Results: See the results of your query quickly.

Cons:

2. Limited Learning Resources: Primarily for practicing, not for beginners.
3. Not Ideal for New Users: Beginners might struggle without prior SQL knowledge.

Top of Form

4. HackerRank (Intermediate to Advanced) 
   Website: HackerRank SQL Challenges 
   Skill Level: Intermediate to Advanced 
   HackerRank offers a variety of SQL challenges and competitions tailored for intermediate and advanced users. The challenges span a wide array of SQL topics, and you can earn badges to showcase your progress. Here’s an example of a more advanced challenge: 

Example: HackerRank’s challenges often require complex SQL queries, such as calculating the average salary of employees in a department. 

— Example SQL Query 

sql 

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SELECT department, AVG(salary) as average_salary   
FROM employees   
GROUP BY department   
HAVING AVG(salary) > 50000;   
 

Key Features: 

1. Challenges and Competitions: Engage with SQL problems in a competitive, game-like format. 
2. Earn Points: Accumulate points and demonstrate your skills with badges. 

Pros: 

3. Fun and Engaging: The challenges make learning SQL enjoyable. 
4. Community Interaction: You can discuss problems, ask questions, and learn from peers. 
5. For All Skill Levels: Offers challenges for both beginners and advanced users. 

Cons: 

6. Some Challenges Are Difficult: Some tasks can be tough, especially for beginners. 
7. Limited Tutorials: Focuses more on problem-solving than on foundational SQL learning. 

5. LeetCode (For Advanced Users) 

Website: LeetCode SQL Problems 

Skill Level: Advanced 

LeetCode is widely recognized for its coding challenges, including SQL problems that are ideal for users aiming to master SQL at an advanced level. The platform also features community discussions and solutions to help you improve. Here’s an example of an advanced SQL challenge: 

Example: LeetCode challenges often involve complex tasks, such as finding the second-highest salary in a database. 

— Example SQL Query 

sql 

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SELECT DISTINCT Salary as SecondHighestSalary   
FROM Employee   
ORDER BY Salary DESC   
LIMIT 1 OFFSET 1;   
 

Notable Features: 

• SQL Puzzles: Approach SQL challenges like solving puzzles. 
• Learn from Others: View solutions from others to gain new insights. 

Pros: 

• Advanced Content: Perfect for those who want to deepen their SQL expertise. 
• Community Interaction: Learn by discussing solutions with other users. 
• Interview Preparation: Many questions are designed to help you prepare for job interviews. 

Cons: 

• Not Beginner-Friendly: This can be tough for beginners to grasp. 
• Limited Learning Structure: It focuses more on problem-solving than on a structured learning approach. 

6.  W3Schools SQL Tutorial (Beginner-Friendly)
   Website: W3Schools SQL Tutorial
   Skill Level: Beginner
   W3Schools provides a comprehensive and beginner-friendly SQL tutorial with interactive examples and exercises. It covers a wide variety of SQL topics, making it an excellent resource for those just starting. Here’s an example of a simple query:

Example: You can practice SQL by retrieving data from a table, such as selecting data from a “customers” table.

— Example SQL Query

sql

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SELECT * FROM customers;

Key Features:

6. Real Database Setup: You set up your own database, giving you a more realistic experience.
7. Hands-On Learning: Learn by directly practicing SQL queries.

Pros:

6. Real-Life Experience: It’s the closest to working with real-world databases.
7. Choice of Database: You can select your preferred database system like MySQL or PostgreSQL.
8. Suitable for All Levels: Whether you’re a beginner or more experienced, this tutorial works for you.

Cons:

6. Database Setup Can Be Challenging: If you’re new, setting up a real database might be tricky.
7. Less Guided Learning: It’s more about practicing and less about structured step-by-step teaching.

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7. SQLBolt (Interactive)
   Website: SQLBolt
   Skill Level: Intermediate
   SQLBolt, previously mentioned, also offers tutorials for intermediate and advanced learners. As you progress, you can tackle more complex exercises, including JOIN operations and subqueries. Here’s an example of an intermediate query:

Example: You can practice SQL by performing JOIN operations between two related tables, such as “orders” and “customers.”

— Example SQL Query

sql

CopyEdit

SELECT customers.name, orders.product 

FROM customers 

JOIN orders ON customers.customer_id = orders.customer_id;

Key Features:

7. Extensive Lessons: Learn a wide range of SQL concepts.
8. Practice as You Learn: It allows you to try SQL queries live within the tutorial interface.

Pros:

7. Comprehensive Learning: Covers everything from basics to more advanced topics.
8. Interactive: You can immediately practice what you’ve learned.
9. Clear and Simple Lessons: Easy-to-follow structure.

Cons:

7. No Real Databases: Lacks practice with real databases.
8. A Lot to Learn: The extensive lessons may feel overwhelming for some users.

• Mode Analytics (Advanced)
  Website: Mode Analytics
  Skill Level: Advanced

Mode Analytics offers an advanced SQL tutorial tailored for data analysis and exploration. This resource is designed for users aiming to utilize SQL for comprehensive data analytics and visualization. It provides opportunities to practice complex queries and data manipulation. Here’s an example of an advanced SQL query:

Example: You can enhance your SQL skills by building intricate data visualizations, such as plotting time series data or designing interactive dashboards.

Example SQL Query (for data visualization):

sql

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SELECT date, revenue 

FROM sales_data 

GROUP BY date 

ORDER BY date;

Key Features:

• Data Analysis Focus: Primarily focuses on using SQL for in-depth data analysis.
• Data Visualization: Allows you to transform data into charts and dashboards for better insights.

Pros:

• In-Depth Analysis: Ideal for those looking to deepen their data analysis skills.
• Practical Skills: Teaches how to apply data to real-world decision-making.
• Great for Analysts: Perfect for individuals pursuing careers that involve heavy data work.

Cons:

• Not Beginner-Friendly: May be challenging for those new to SQL.
• Limited SQL Coverage: Does not cover all aspects of SQL, particularly database management.

Top of Form

SQL Pad (Intermediate to Advanced)
Website: SqlPad
Skill Level: Intermediate to Advanced

SQL Pad provides an interactive platform featuring a comprehensive library of real-world SQL challenges. It’s ideal for those aiming to improve their SQL skills through hands-on problem-solving. The platform offers opportunities to work on data problems from various fields. Here’s an example of a more advanced challenge:

Example: You can practice SQL by tackling complex challenges like optimizing queries for better performance or analyzing datasets to derive actionable insights.

Example SQL Query (for data analysis):

sql

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SELECT product_category, AVG(revenue) AS avg_revenue 

FROM sales_data 

GROUP BY product_category 

HAVING AVG(revenue) > 1000 

ORDER BY avg_revenue DESC;

Key Features:

• Real-Life Problems: Solve practical data issues encountered in various jobs.
• Hands-On Learning: Improve your SQL skills by working directly on real-world problems.

Pros:

• Solve Real-World Challenges: Learn to address actual data problems.
• Wide Range of Challenges: Offers a variety of problems to practice on.
• Work-Ready Skills: Great practice for anyone planning to work with data.

Cons:

• Not Beginner-Friendly: It may be too difficult for those new to SQL.
• Paid Features: Some features require payment for full access.

Choosing the right platform depends on your current skill level and learning goals. Each platform offers a unique way to learn and practice SQL, so try them out to find the one that best fits your needs. Happy SQL learning!

1. Your Local Database (Practical)
   Skill Level: All Levels
   To gain hands-on experience, try setting up your own local database using software such as MySQL, PostgreSQL, or SQLite. This will give you the opportunity to create databases, input data, and execute queries. Here’s an example to get you started:

Example: Create a basic table in your local database and populate it with data:

— Example SQL Query
CREATE TABLE products (
product_id INT PRIMARY KEY,
product_name VARCHAR(50),
price DECIMAL(10, 2)
);
INSERT INTO products (product_id, product_name, price)
VALUES (1, ‘Widget’, 19.99), (2, ‘Gadget’, 29.99), (3, ‘Doodad’, 9.99);

How to Utilize SQL Practice Platforms
To effectively test your SQL skills, begin with the fundamentals and progressively tackle more complex exercises. While practicing, make sure to pay attention to the feedback provided by the platform. This feedback is valuable in helping you recognize both your strengths and areas for improvement, as well as in learning from your errors.

Here are some extra tips for practicing SQL:

• Practice consistently. The more you practice, the more proficient you’ll become in SQL.
• Explore different resources. With many SQL practice tools available, try various ones until you find the best fit for your learning style.
• Push yourself. Take on more difficult exercises, even if you make mistakes. Challenging yourself will help you improve your SQL skills.
• Seek assistance. If you’re stuck on an exercise, don’t hesitate to ask for help from a friend, mentor, or online community.

Conclusion
Practicing SQL is a worthwhile investment for your career, and the platforms outlined in this tutorial offer resources for all skill levels. Begin with beginner-friendly exercises, gradually move on to more advanced challenges, and be sure to apply your skills in real-world projects. With consistent practice and growing confidence, you’ll become a skilled SQL user. Happy querying!