Introduction to MySQL

Introduction

Nearly every application — a to-do app, a social network, an online store — needs somewhere to permanently store its data. Databases are built specifically for this job, and MySQL is one of the most widely used database systems in the world.

This lesson introduces what a database actually is, what MySQL specifically provides, and the basics of SQL — the language you will use throughout this entire course to talk to it.

What is a Database?

A database is an organized collection of data, stored so it can be efficiently accessed, managed, and updated. Instead of scattering data across text files, a database keeps everything structured, searchable, and safe from accidental corruption.

What is MySQL?

MySQL is a relational database management system (RDBMS) — software that lets you create, manage, and query relational databases. It is free, open-source, and was first released in 1995.

"Relational" means data is organized into related tables, rather than one giant unstructured blob. For example, a "students" table and a "grades" table can be linked together through a shared ID.

What is SQL?

SQL (Structured Query Language) is the language used to communicate with a relational database — to create tables, insert data, and ask questions about that data.

SELECT name, marks
FROM students
WHERE marks >= 60;

+-------+-------+
| name  | marks |
+-------+-------+
| Alex  | 78    |
| Sam   | 65    |
+-------+-------+

Tables: Rows and Columns

Think of a table like a spreadsheet. Each column represents one piece of information (like a name or an age), and each row represents one complete record.

This example table is named "students." Each row is one student, and each column stores one attribute about that student.

What Can MySQL Do?

Where MySQL Is Used

Example: A First Look at SQL

You do not need to understand every keyword yet — this is just a preview. Notice how SQL reads almost like a sentence.

CREATE TABLE students (
    id INT PRIMARY KEY,
    name VARCHAR(50),
    marks INT
);

INSERT INTO students VALUES (1, 'Alex', 78);

SELECT * FROM students;

+----+------+-------+
| id | name | marks |
+----+------+-------+
| 1  | Alex | 78    |
+----+------+-------+

Common Mistakes

Best Practices

Frequently Asked Questions

Key Takeaways

Summary

MySQL is a free, open-source relational database system that stores data in structured tables and is controlled using SQL. It has been a foundational piece of web development for decades.

In this lesson, you learned what a database is, what MySQL specifically provides, how tables organize data into rows and columns, and where MySQL is used today. Next, you will explore the history behind MySQL.