You Whaaat? Yes, SQL, aka Structured Query Language. As boring as this sounds SQL is probably your best friend if you start building databases and adding stuff to your app. As most bigger application relies on some sort of data storing magic, time to dig in SQL. A while ago, I found this short tutorial for learning the basics of SQL and I think it is way better than the nowadays super limited Codecademy website.
A database basically is great for
- keeping your data separate from your code
- helps during backups
- this way data is available for later analysis
- easy to reach your database via APIs
Basically, if you want to deal with any data, learn SQL first. Apparently, it is also great for hacking. [SQL injection is a code injection technique, used to attack data-driven applications, in which nefarious SQL statements are inserted into an entry field for execution (e.g. to dump the database contents to the attacker).]
So go on, DROP some TABLEs.
Also, here is a cheat sheet.