MySQL Multi-Aggregated Rows in Crosstab Queries
MySQL's crosstabs contain aggregate functions on two or more fields, presented in a tabular format. In a multi-aggregate crosstab query, two different functions can be applied to the same field or the same function can be applied to multiple fields on the same (row or column) axis. Rob Gravelle shows you how to apply two different functions to the same field in order to create grouping levels in the row axis.