Aggregations

Aggregations are a way to take data as a whole and apply calculations to them, such as counts or sums of data columns. New to BIRT 2.3+ is the aggregation visual component. In newer versions of BIRT, the developers have broken away from the older, scripting based aggregations. With improvements made in the 2.5 series, it is now possible to do some very powerful and interesting things such as using aggregations in groupings for charts, which wasn't possible in BIRT before. Let's take a look at how to build a simple count aggregation for the employees in our offices.

1. 1. Create a new report titled employeeGroupCount.rptDesign.

2. 2. Create a new Data Source off the Classic Models sample database.

3. 3. Create a new dataset called dsEmployeeOffices using the following query:

   select
   EMPLOYEES.EMPLOYEENUMBER,
   OFFICES.OFFICECODE,
   OFFICES.CITY,
   OFFICES.STATE
   from
   EMPLOYEES,
   OFFICES
   where
   OFFICES.OFFICECODE = EMPLOYEES.OFFICECODE
   

4. 4. Right-click on dsEmployeeOffices and select Insert in Layout...