12 of 15 SQL Basics with Oracle - Aggregate (grouping) functions and the GROUP BY clause
This video explains the GROUP BY clause and some of the aggregate functions: sum, count, average, maximum, minimum, count(distinct ...), etc. An example of using an aggregate function would be to group students by major and only show the number of students in each major, not individual student information. (12 of 15) There is also an "Advanced SQL" series. (Search for "databasemec" for tutorials using SQL Server.)
