Best way to learn SQL

How I Learned SQL (And How You Can Too)

I’m Brandon, CEO and Co-Founder of Outerbase. We provide an AI-powered layer on top of your database that allows you to edit, view, query and visualize your data even faster. However, even with AI's help, it is still good to understand what's going on under the hood. That is why even in 2025 I still recommend learning SQL.

A non-technical friend of mine recently asked me what is the best way to learn SQL. They work as a Product Manager and wanted some basic skills. Here’s how I learned, plus some tips that might help you get going.

Why SQL Matters

SQL (Structured Query Language) is how we talk to relational databases. Here’s why it’s important:

• Search and filter data: e.g., “Find all customers who signed up last month.”
• Update records in bulk: e.g., add a new column or reset thousands of values at once.
• Join related tables: e.g., see product sales alongside customer data.
• Secure and structure information: relational tables keep data organized and safe.

Major databases like PostgreSQL, MySQL, and SQL Server all use SQL. Once you know the basics, you can answer data questions on your own.

Step 1: Start With a Tutorial

A structured tutorial helps you learn faster. Some good places to begin:

• Intro to SQL on Outerbase – Covers the basics, with interactive lessons right in your browser.
• W3Schools SQL Tutorial – Classic text-based examples.
• Codecademy: Learn SQL – Interactive approach that walks you through writing queries.

Any of these will give you a strong foundation.

Step 2: Practice With Real Data

Reading about SQL is fine, but you learn the most by writing queries. Spin up a local or cloud database (PostgreSQL, MySQL, or SQL Server) and create a small table:

CREATE TABLE products (
  product_id SERIAL PRIMARY KEY,
  name VARCHAR(255),
  price DECIMAL(10,2)
);

INSERT INTO products (name, price) VALUES
('Laptop', 999.99),
('Mouse', 24.99),
('Keyboard', 49.99),
('Monitor', 199.99);

Try a few queries:

-- Fetch all products:
SELECT * FROM products;

-- Find the product with the highest price:
SELECT name, price
FROM products
ORDER BY price DESC
LIMIT 1;

Seeing actual results is the quickest way to learn.

Step 3: Solve Real Problems

It sticks better if you connect SQL to real situations. Think about questions that matter to you:

1. Which item has the highest price?
2. Change the price of all “Mouse” items to 19.99.
3. Delete items cheaper than $25.

Here’s how that might look:

-- 1. Most expensive item:
SELECT name, price
FROM products
ORDER BY price DESC
LIMIT 1;

-- 2. Update 'Mouse' price:
UPDATE products
SET price = 19.99
WHERE name = 'Mouse';

-- 3. Delete cheap items:
DELETE FROM products
WHERE price < 25.00;

Practicing on real projects cements your new skills.

Step 4: Focus on Core Commands First

SQL is big, but most of the time you’ll use these:

• SELECT (fetch data)
• WHERE (filter rows)
• JOIN (connect multiple tables)
• GROUP BY (aggregate rows, often with COUNT, SUM, or AVG)
• ORDER BY (sort results)
• INSERT (add new rows)
• UPDATE (change existing rows)
• DELETE (remove rows)

For more info:

• SQL SELECT on Outerbase
• SQL WHERE on Outerbase
• SQL JOIN on Outerbase

These microsites let you run queries in your browser on a real database.

Step 5: Learn Indexing and Performance

As your skills grow, you’ll want your queries to run faster. That’s where indexing helps. For example, in PostgreSQL:

CREATE INDEX idx_price
ON products (price);

Now the database can find rows faster when sorting or filtering by price. To learn more, check out the PostgreSQL Docs or MySQL Docs.

Step 6: Browse Stack Overflow Q&A

Stack Overflow has a massive library of SQL questions and answers. For example, someone might ask how to use GROUP BY:

SELECT product_id, SUM(price) AS total_price
FROM products
GROUP BY product_id
ORDER BY total_price DESC;

Explore the SQL tag on Stack Overflow to see common questions and solutions.

SQL Tips for Product Managers

1. Learn Enough to Be Effective You only need enough SQL to answer your own questions without waiting on others.
2. Use a Sandbox Experiment in a test environment, not on production data. Everyone makes mistakes at first.
3. Ask for Help AI, Data engineers, and developers can save you time when you get stuck.
4. Know Your Limits Hand off complex or performance-heavy queries to AI or specialists.

More Useful Resources

• Intro to SQL on Outerbase – Interactive, browser-based tutorials using SQLite.
• W3Schools SQL Tutorial – Classic, text-based lessons.
• Codecademy: Learn SQL – Step-by-step lessons with instant feedback.
• PostgreSQL Docs – In-depth details about PostgreSQL.
• MySQL Docs – Official reference for MySQL.
• SQL Server Docs – Microsoft’s official SQL Server resource.

Final Thoughts

You can learn SQL basics in a few days. Mastering it can take a lifetime, but you don’t have to be a pro to do useful things. Once you know SELECT, JOIN, and GROUP BY, you’ll be amazed how many questions you can answer yourself.

Want to jump in? Try Intro to SQL on Outerbase or a guided course on Codecademy or W3Schools. The key is to write real queries and see how the database reacts.