CHAPTER 11Group Functions

Exam Objectives

In this chapter you will learn to

• 051.5.1 Identify the Available Group Functions

• 051.5.2 Describe the Use of Group Functions

• 051.5.3 Group Data by Using the GROUP BY Clause

• 051.5.4 Include or Exclude Grouped Rows by Using the HAVING Clause

Single-row functions, explored in Chapter 10, return a single value for each row in a set of results. Group or aggregate functions operate on multiple rows. They are used to count the number of rows or to find the average of specific column values in a dataset. Many statistical operations, such as calculating standard deviation, medians, and averages, depend on executing functions against grouped data and not just single rows.

You will examine group functions ...

Get OCA/OCP Oracle Database 11g All-in-One Exam Guide now with the O’Reilly learning platform.

O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.