Oracle SQL: the Essential Reference

Chapter 5. SQL Functions

Oracle implements a large number of built-in functions you can invoke from SQL or PL/SQL. If you're going to be working in either of these languages, you must have a good knowledge of these functions. If you're working with SQL, you'll also have a number of aggregate functions at your disposal. All are documented in this chapter, along with examples. Many of these examples show how to invoke the functions via SQL*Plus; for more information, see Chapter 6.

This chapter describes SQL functions within the following categories:

• Aggregate functions

• Numeric functions

• Character functions

• Date functions

• Conversion functions

• Other (miscellaneous) functions

A note about function parameters is in order. Each function description contains a syntax block showing the parameters that may be passed to a function. In many cases, the parameter descriptions are obvious, and I've chosen not to specifically describe them. The ABS function is an example of this type of description. If you read the function description and look at the examples, it will be obvious how the function can be used. When necessary, I've included detailed parameter descriptions for other functions.