No doubt, you will have seen calculations before now. SQL allows you to include calculated data in your queries.
In this chapter, we’ll look at some important ideas about the different types of data and how they can be calculated.
Don’t get too carried away with calculations in your SQL. The database is more concerned with maintaining and accessing raw data. However, it’s useful to be able to take your raw data and make it more useful to the task at hand.
DBMSs vary widely in their ability to perform calculations. ...
