Learn MySQL Programming
Master SQL from basics to advanced topics with practical, production‑style examples. Perfect for beginners and developers who want to query data effectively.
MySQL Programming Tutorial
Learn SQL step-by-step using MySQL: from installation to writing efficient queries with joins, aggregates, transactions, and constraints.
UNION
Combine results from multiple queries. Use UNION ALL to keep duplicates. Each part must select the same number of columns in the same order.
SELECT name FROM customers\nUNION\nSELECT name FROM archived_customers;- Use
UNIONto deduplicate across sources;UNION ALLpreserves all rows. - Wrap complex unions in views to simplify reuse.
Practice as You Learn
Use the MySQL editor to run queries and adjust examples. Build confidence by experimenting with different WHERE clauses, JOINs, and aggregates.
Frequently Asked Questions
Do I need to install MySQL to learn SQL?
No. You can practice SQL using our online MySQL editor. Installing MySQL locally is recommended for deeper learning and real-world workflows.
What are the most common SQL commands?
The essentials include SELECT, INSERT, UPDATE, DELETE, CREATE TABLE, and JOIN. Mastering these gives you a strong foundation.
How do I avoid slow queries?
Use proper indexes, filter with WHERE, and limit scanned rows. Review query plans with EXPLAIN and avoid SELECT *
Is MySQL different from SQL?
SQL is the language. MySQL is a database system that uses SQL. Syntax is mostly standard, with a few MySQL-specific features.