About report parameters and filters
Report parameters provide a mechanism for collecting values from a report user or a program. They are typically used in filters to collect information that determines the data to display in a report. Actuate BIRT Designer supports all the functionality of parameters and filters available in the open-source version, and provides additional features.
In open-source BIRT Report Designer, the following expression in the filter tool is an example of how a filter uses a report parameter to obtain the filter value at run time:
row["Total"] Greater than or Equal params[Sales Total].value
The field to evaluate (row["Total"]) and the operator that determines the type of filter test (Greater than or Equal) are specified at design time. At run time, the report user supplies the parameter value, which, in this example, is a sales total, such as 10000.
In Actuate BIRT Designer, report parameters and filters are enhanced to support dynamic filter conditions, which provide users more control over what data they see in the report. Instead of specifying only the value on which to filter, the report user can specify conditions, such as Total Less than 10000, or Total Between 10000 and 20000, or Total Greater than 20000. The user can also choose to view all totals; in other words, the user can choose to omit the filter condition.
Another enhancement is that these filters can modify the underlying query so that filtering occurs in the database. This functionality applies when accessing a database through an information object or a JDBC connection for query builder data source. When using these data source types, only data rows that meet the filter criteria are retrieved from the database. By retrieving a limited number of rows, Actuate BIRT Designer’s performance improves.
This chapter describes how to create report parameters and filters to enable dynamic filtering. For information about other types of parameters and filters, see BIRT: A Field Guide.

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