Introduction to SQL, MySQL and MariaDB

SQL (Structured Query Language) is the standard language for managing and manipulating relational databases. MySQL and MariaDB are popular database management systems that use SQL. In this tutorial, we’ll cover the basics of SQL and how to work with MySQL and MariaDB.

What Is SQL?

SQL is a language used to interact with relational databases. It allows you to create, read, update, and delete data. Here’s an example of a basic SQL query:

SELECT * FROM users;

Installing MySQL or MariaDB

Both MySQL and MariaDB can be installed locally or used through a hosting provider. To install locally:

1. Download MySQL: Visit MySQL Downloads and follow the instructions for your operating system.
2. Download MariaDB: Visit MariaDB Downloads.
3. Use a Package: If you’re using tools like XAMPP, MySQL or MariaDB may already be included.

Connecting to the Database

Once installed, start the database server and connect using a client like the MySQL command-line tool or phpMyAdmin:

mysql -u root -p

Enter your password to connect to the MySQL/MariaDB server.

Creating a Database

Create a new database using the CREATE DATABASE command:

CREATE DATABASE testdb;

Switch to your new database:

USE testdb;

Creating a Table

Define a table to store data:

CREATE TABLE users (
        id INT AUTO_INCREMENT PRIMARY KEY,
        name VARCHAR(50),
        email VARCHAR(100)
    );

Inserting Data

Add data to your table using the INSERT statement:

INSERT INTO users (name, email) VALUES ('Alice', 'alice@example.com');

Querying Data

Retrieve data from your table using the SELECT statement:

SELECT * FROM users;

Updating Data

Modify existing data using the UPDATE statement:

UPDATE users SET email = 'alice_new@example.com' WHERE name = 'Alice';

Deleting Data

Remove data using the DELETE statement:

DELETE FROM users WHERE name = 'Alice';

Next Steps

Explore advanced SQL features like joins, indexing, and stored procedures. Practice using MySQL or MariaDB to manage real-world data. Understanding databases is essential for back-end development and data-driven applications.