Oracle SQL Recipes: A Problem-Solution Approach

Chapter 2. Summarizing and Aggregating Data

In this chapter we'll introduce recipes for working with your data at a higher level, where grouping, summaries, and the bigger picture are important. Many of the recipes we'll explore cover common or tricky reporting scenarios, the kind you encounter in a business or professional setting. Most organizations ask for reports about who sold what to whom, how many people, sales, or activities happened in a given time frame, trends across regions or customer groups, and the like.

Many people are familiar with some of the basic methods Oracle provides for performing summaries and aggregates. But often developers and DBAs will try to execute more complex calculations in their applications—and tie themselves ...