Getting started with databases

Any large scale web application needs some kind of storage to maintain its state. Saving the state as a raw text file or in binary file format, like we did in the Shopping List iOS app with the help of UserDefaults, is not ideal and does not scale or perform well. To solve this problem, databases were created, which are collections of tables that can save data in a structured format, with the ability to retrieve and save data at very high speeds. Also, databases decouple data from our application and data can be transferred or consumed by another application, making the data portable. You can create relationships between tables inside of a database, just like you would create relationships in between objects in object-oriented programming languages. Such databases are known as relational databases. This helps us organize data just like we would...