4
Functions

Form ever follows function.

Louis Henri Sullivan, The Tall Office Building Artistically Considered

Functions are similar to operators in that they manipulate data items and return a result. Functions differ from operators in the format of their arguments. This format allows them to operate on zero, one, two, or more arguments:

function(argument, argument, ...) 

This chapter describes two types of functions:

• SQL Functions

• User-Defined Functions