> ## Building a Report That Contains Subreports

> A report can contain multiple reports called subreports. A subreport is a report that appears inside another report. BIRT supports many ways of arranging subreports within a report, such as:

> | Displaying multiple reports, one after another. For example, you can display the top ten customers, top ten sales managers, and top ten products.

> | Displaying multiple reports next to one another. For example, you can display general employee information and employee salary history.

> | Displaying one report within another. For example, you can display detailed mutual fund performance within general fund information.

> BIRT also supports combining any of these configurations. Each subreport can access a different data source, use data from its own set of tables, and specify its own data selection criteria. Subreports can be linked to one another, meaning that the data of one report determines what data appears in the other. Alternatively, subreports can be independent of each other.

> Always create, lay out, and test each subreport before creating the next one, and verify that the subreport displays the correct data. If you skip intermediate testing, it can be difficult, if you have problems, to determine which subreport causes an error.

(c) Copyright Actuate Corporation 2013