SQL lets you control and query relational databases with precision. This guide shares the key commands developers need to know, along with examples you can drop into your projects right away.

Key Commands You’ll Use Regularly

SELECT

SELECT name, age FROM users WHERE age > 25;

Retrieves users older than 25.

INSERT

INSERT INTO users (name, age) VALUES ("Maya", 29);

Adds a new user.

UPDATE

UPDATE users SET age = 30 WHERE name = "Maya";

Changes Maya’s age.

DELETE

DELETE FROM users WHERE name = "Maya";

Removes Maya from the table.

CREATE TABLE

CREATE TABLE products (id INT, name VARCHAR(100));

Sets up a table for products.

JOIN

SELECT U.name, O.amount FROM users U INNER JOIN orders O ON U.id = O.user_id;

Combines user and order data into one result.

LIMIT

SELECT * FROM users LIMIT 10;

Returns the first 10 rows from the table.

FAQ

Is SQL still worth learning?

Absolutely. It’s the core of most analytics, backend systems, and admin tools.

Do all SQL databases support these commands?

Yes for the basics, though some systems offer extra features or slightly different syntax.

What’s a good tool to run SQL queries?

DbVisualizer is a strong option—it works with many databases and includes helpful dev features.

What’s next after basics?

Start chaining commands, use subqueries, and explore performance tuning.

Conclusion

If you’re building apps or working with data, these SQL commands will show up constantly. Learn them once, and they’ll serve you across every project, from data reporting to app development. With the right client, writing these queries becomes even faster.

Check the Glossary of the SQL Commands You Need to Know article for more examples.