This chapter described a wide variety of functions. Functions are basically predefined rules for transforming a set of values into another value. Just as spreadsheets provide built-in functions for manipulating data, SQL provides similar capabilities. In addition to covering basic character, date/time, numeric, and conversion functions, we also explained how to create composite functions from two or more of these functions.
Because there are simply so many available functions with widely varying possibilities, it’s impossible to discuss every nuance of every available function. The thing to remember is that functions can be easily looked up in a database’s help system or reference guide when they need to be used. Online reference material will provide details on exactly how each function works and the proper syntax.
In our next chapter, we’ll take a break from columnlist issues and talk about something a little more interesting: how to sort data. Sorts can serve lots of useful purposes and satisfy the basic desire of users to view data in some type of order. With the sort, we will begin to think of the entire way in which information is presented, rather than with just bits and pieces of individual data items.