Databases

MySQL Introduction

Databases 38 min read

MySQL Introduction

Another very popular relational database system is MySQL.

MySQL has been widely used for websites, business software, and backend systems for many years.

If you understand SQL and databases, learning MySQL becomes much easier.

What Is MySQL?

MySQL is an open-source relational database management system (RDBMS).

It stores data in tables and uses SQL to manage data.

Like PostgreSQL, MySQL usually runs as a database server that applications connect to.

Why Learn MySQL?

MySQL is important because it is:

widely used
beginner-friendly
fast for many workloads
common in web development
supported by many hosting providers
used in real businesses

Where MySQL Is Used

MySQL is used in:

websites
e-commerce platforms
content systems
dashboards
internal business tools
backend APIs

MySQL vs SQLite

SQLite

file-based
no server
great for local apps

MySQL

server-based
supports many users
production deployments
strong ecosystem

MySQL vs PostgreSQL

MySQL

very common in web hosting
popular beginner choice
strong performance for common apps

PostgreSQL

known for advanced features
powerful complex queries
strong standards support

Both are excellent choices.

Basic SQL in MySQL

Create table:

sql

CREATE TABLE users (
    id INT AUTO_INCREMENT PRIMARY KEY,
    name VARCHAR(100),
    active BOOLEAN
);

What Is AUTO_INCREMENT?

Automatically increases the id value for each new row.

Example ids:

text

1
2
3

Insert Data

sql

INSERT INTO users (name, active)
VALUES ('Tom', TRUE);

Read Data

sql

SELECT * FROM users;

Update Data

sql

UPDATE users
SET active = FALSE
WHERE id = 1;

Delete Data

sql

DELETE FROM users
WHERE id = 1;

Connecting from Python

A common library is:

text

mysql-connector-python

Install:

bash

pip install mysql-connector-python

Example:

python

import mysql.connector

conn = mysql.connector.connect(
    host="localhost",
    user="root",
    password="secret",
    database="mydb"
)

Parameterized Query Example

python

cursor.execute(
    "SELECT * FROM users WHERE id = %s",
    (1,)
)

Use parameters instead of building SQL strings manually.

Important Concepts

Host

The server address.

Example:

text

localhost

User

Database account name.

Password

Account password.

Database

The selected database to use.

Common Beginner Errors

Server Not Running

MySQL service must be running.

Wrong Password

Check credentials carefully.

Wrong Database Name

Use an existing database.

Missing Driver

Install the connector package.

Code Along

Design two tables for an online store in MySQL.

Example:

products
orders

Mini Challenge

Design a movie app.

Tasks:

Create table name
Choose 4 columns
Pick a primary key
Write one INSERT query
Write one SELECT query

Real World Use Case

MySQL powers websites, e-commerce stores, CMS systems, dashboards, and backend business apps.

Quiz

What is MySQL?
How is MySQL different from SQLite?
What does AUTO_INCREMENT do?
What Python package connects to MySQL?
Why is MySQL popular?

Assignment

Write a schema for a library system with books, members, and loans tables.

Summary

You learned what MySQL is, how it compares with SQLite and PostgreSQL, and how Python connects to it.