Explore creating scalable PHP web applications, structuring code efficiently, managing data storage, and implementing automated testing to ensure robustness and maintainability in real-world projects.

docker.tar.gz

Serve /usercode

Run index.php (quiet composer install)

Serve /usercode (quiet composer install)

execute_apcu

This course is for people who have already learned the basics of PHP (or just finished the "Learn PHP from Scratch" course) and want the bigger picture of making big web applications with this language.

First, you'll learn how all PHP web applications communicate with the world and how to turn multiple source code files into one application. Then you'll learn multiple approaches to structuring the whole application. It will help you write code that's easy to maintain. Also, this is a common topic for job interview questions.

Next, you'll learn different data storage methods, from user sessions to databases. This course doesn't duplicate the official documentation but instead provides an overview of the various tools you can use. You'll learn how to use them in PHP, their tradeoffs, and how to pick what's best for your project.

Finally, you'll learn how to make automated tests for your project to ensure that it works as expected.

Developing Web Applications with PHP

Whenever an application needs a long-term data store, our default choice is a database. A relational database is an old and reliable way to store arbitrary data in computer systems.

Relational databases are storage for structured data. They consist of multiple **tables**, and each table contains multiple **records** sharing the same set of **attributes**.

For example, imagine the information we can store about a theater play. It could be the name, author, duration, and a description. We can also add an ID to distinguish it. Each play has a different name, but it always has one. The same goes for the author and description. The plays have different data but a common set of properties.

We can put all the information into a table in which each row is a separate play, and each column is one thing we can know about every play, like the name or author. We can save such a structure in an Excel table, a CSV file, or a database. Relational databases store data that look like tables.


Such databases are relational, because, in relational database theory, tables are called relations. This term is rarely used with its original meaning now.

This chapter is an introduction to relational databases. The topic is big enough for a separate course, so it’s more like a tour of the features of relational databases.


## Relational database structure

Usually, the application data doesn't fit into a single table. Instead, we have multiple tables with **interconnected data**.

For example, let's look at a database schema for theater seat reservations.

Such databases are relational, because, in relational database theory, tables are called relations. This term is rarely used with its original meaning now.

This chapter is an introduction to relational databases. The topic is big enough for a separate course, so it’s more like a tour of the features of relational databases.


# Relational database structure

Usually, the application data doesn't fit into a single table. Instead, we have multiple tables with **interconnected data**.

For example, let's look at a database schema for theater seat reservations.

Learn about relational databases, their structure, and indexes.

Introduction

Communicating with the Client

Static Web Application

Structuring Code Files

Application Architecture Basics

PHP-Based Web Application

Storing State

Databases

Using a Database in the PHP Application

Testing

Testing the PHP Application

Advanced Architecture Patterns

Final Assessment

Conclusion

Relational Databases