Databases

Storage for data related to your webapps that lasts longer than a single session

Sessions are temporary, so we need more permanent storage

A webapp can store information in a Session only temporarily.

Once the web browser is closed, any information the user entered that was stored in the session is lost.

So, if we want a web app to remember some information entered by the user from one session to the next, we need to store it somewhere more permanently.

Why not just write to a file

For a desktop app where there is likely to be only one user at a time, writing to the file system is often a way that data is stored between sessions.

For web apps, though, there are at least three reasons that we tend to use databases rather than reading or writing regular files:

Types of Databases: SQL vs. NoSQL

There are two main types of databases in common use with web applications:

Securing your database

Before deploying any system that store persistent data on a public-facing server (e.g. a Heroku server), it is important to secure your database. This means:

What are we using in this course?

Examples