Lesson 12. Summarizing Data
In this lesson, you will learn what the SQL aggregate functions are and how to use them to summarize table data.
Using Aggregate Functions
It is often necessary to summarize data without actually retrieving it all, and Oracle provides special functions for this purpose. Using these functions, Oracle queries are often used to retrieve data for analysis and reporting purposes. Examples of this type of retrieval include the following:
Determining the number of rows in a table (or the number of rows that meet some condition or contain a specific value)
Obtaining the sum of a group of rows in a table
Finding the highest, ...