In this lesson, you'll learn what functions are, what types of functions DBMSs support, and how to use these functions. You'll also learn why SQL function use can be very problematic.
Like almost any other computer language, SQL supports the use of functions to manipulate data. Functions are operations that are usually performed on data, usually to facilitate conversion and manipulation.
An example of a function is the
RTRIM() that we used in the last lesson to trim any spaces from the end of a string.
Before you work through this lesson and try the examples, you should be aware that using SQL functions can be highly problematic.
Unlike SQL statements ...