What is a SQL database? SQL is short for Structured Query Language. It's a language that allows you to interface with Data. Data can be arranged in rows and columns, similarly to a spreadsheet. You use English type queries to get and set data in the database. SQL contains a whole world of functionality to work with and manipulate data.

Essentially, you send commands and queries to the server. The server processes the commands, retrieves the data, and outputs it on the screen. Once you've learned SQL, you can then use it with a back end server language such as PHP, Node, Python, and many others. With these back end languages, you can then go on to write full applications. The back end language would be the language that you use to ask the database for data, generate the application screens, that then shows the data to a user via a browser or a desktop/mobile application.

SQL is just one layer of a stack of technologies that reside to create a full application. Some people go on to work within this whole stack of software, while others specialize in various layers of the software stack. It's up to you how far you want to go.

This guide is for beginners. This guide isn't trying to be an exhaustive reference to SQL. There is a lot to SQL that is not covered here. I'm not trying to overwhelm a beginner with too much information. This guide is mostly written with MySQL in mind. To see exact documentation for the most used MySQL statements, please visit the MySQL reference site

In this guide, I'll be using the open source community edition of Oracle MySQL version 8.0. Please be aware that there are differences in prior versions where things not work properly if executed in older versions or incompatible forks.

There are differences between different vendors of databases. Some features that work great in MySQL don't work at all in software such as Microsoft SQL Server and vice versa. I'll try to highlight those differences, but this guide is heavily skewed towards MySQL.