Data is probably the cornerstone of most web applications. Sure, your application has to be pretty, fast, error-free, and so on, but if something is essential to users, it is what data you can manage for them. From this, we can extract that managing data is one of the most important things you have to consider when designing your application.
Managing data implies not only storing read-only files and reading them when needed, as we were doing so far, but also adding, fetching, updating, and removing individual pieces of information. For this, we need a tool that categorizes our data and makes these tasks easier for us, and this is when databases come into play.
In this chapter, you will learn about:
Schemas and tables
Manipulating and querying data
Using PDO to connect your database with PHP
Indexing your data
Constructing complex queries in joining tables