Chapter 13. Aggregating Data
One of the key features of any report is the ability to display summary, or aggregate, information. For example, a sales report can show the overall sales total; sales subtotals by product type, region, or sales representatives; average sales figures; or the highest and lowest sales figures.
Aggregating data involves performing a calculation over a set of data rows. For a simple listing report, the aggregate calculations are performed over all the data rows in the report. The listing report in Figure 13-1 displays aggregate data at the end of the report.
Figure 13-1. A simple listing report that displays detail and aggregate ...