Learn MySQL

What Is MySQL?

MySQL is a relational database management system (RDBMS) that organizes data into tables made up of rows and columns, where each table typically represents one kind of entity such as customers, orders, or products, and relationships between tables are built using shared key columns. First released in 1995, MySQL is now owned by Oracle Corporation and is available under both an open-source GPL license and commercial licenses.

MySQL runs as a server process that listens for connections, usually on port 3306. Client programs, such as command-line tools, web applications, or admin panels, connect to the server, send SQL statements, and receive results back. This client-server model lets many applications and users share the same underlying data safely at the same time.

Why Developers Choose MySQL

• Free and open source, with no licensing cost for most use cases
• Extremely fast for the read-heavy workloads common in web applications
• Runs on Windows, Linux, and macOS without any code changes
• Huge ecosystem: works with PHP, Node.js, Python, Java, and virtually every framework
• Backbone of the LAMP stack (Linux, Apache, MySQL, PHP) that powers millions of sites

Databases, Tables, and Rows

A single MySQL server can host many databases at once, each acting as an independent container for related tables. Inside a database, a table defines a fixed set of named columns, each with a data type such as INT, VARCHAR, or DATE, and every row you insert must fit that structure. This rigid structure is what makes relational databases predictable and reliable to query.

Running Your First Queries

SHOW DATABASES;

CREATE DATABASE shopdb;
USE shopdb;

CREATE TABLE customers (
  customer_id INT AUTO_INCREMENT PRIMARY KEY,
  name VARCHAR(100),
  email VARCHAR(150),
  country VARCHAR(50)
);