BIRT Cascading Parameters

Virgil Dodson

This example demonstrates how to build a BIRT report that uses a cascaded parameter group. A cascaded parameter group allows a group of parameters to be interlinked, where selecting a value for the first parameter affects the choices available in the subsequent parameters. Cascaded parameters can be tied to one or more Data Sets. The Data Sets populate each level of the cascade. Combined with Data Set parameters this offers very good flexibility for culling of returned data for a report.<br />
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In this particular example we demonstrate cascading parameters by producing a order details report. The user of the report is presented with a cascaded parameter group that contains customers and orders. When a customer is selected the orders for the customer is updated in the parameter selection. After the order is selected a order detail report is generated for the selected order. This report contains three Data Sets. The customers Data Set is used to retrieve customers for the first level of the cascade. The orders Data Set is used to display orders in the parameter cascade for the selected customer. This Data Set uses the customer selected as part of the where clause and demonstrates tying a report parameter to a Data Set parameter. The final Data Set is orderdetails and uses the order report parameter in its where clause to retrieve the details about the selected order. This is the only Data Set used in the actual output of the report.