Databases and Persistence

So far, your application works—but there’s a major problem.

It does not remember anything.

The Problem

Try this:

• Open your app
• Enter your name in the form
• Submit it
• Refresh the page

What happens?

Your data is gone.

Every time your app restarts, everything is lost.

Why This Happens

Right now, your app only processes data temporarily.

• The user submits data
• The app uses it
• Then it disappears

There is no storage.

What We Need

Real applications need to:

• Save user data
• Store information permanently
• Retrieve it later

This is where databases come in.

What is a Database?

A database is a system used to store data so it can be accessed later.

Instead of losing data, your app can:

• Save it
• Read it
• Update it
• Delete it

What You Will Learn

In this module, you will learn how to:

• Store data using a database
• Create and manage tables
• Insert and retrieve data
• Connect your Flask app to a database
• Build real data-driven applications

How This Connects to Your App

You will upgrade your current project.

Right now:

• Users enter a name → it disappears

After this module:

• Users enter a name → it is saved
• You can view all users
• You can manage stored data

Outcome

By the end of this module, your application will:

• Remember data
• Store users
• Work like a real backend system

Let’s start by understanding how data is organized inside a database.