Understanding the Value of Parameters

By using parameter fields that allow business users to select from a list of one or more parameter field values (such as district, country, or account type), you can make reports more valuable for the business users while limiting the volume of data that the report retrieves. For example, a sales report is likely to be more valuable for the sales professionals if it allows them to select their specific territory or district, while the report runs more efficiently because it retrieves only the desired data and not an unnecessarily large data set. Parameter fields can prompt users for a variety of information to be used in a number of ways within reports, such as controlling the sort order, grouping order, record selection (filter), report title and descriptions, and other object values.

Parameter fields prompt the business user of a report to enter information presenting a question that the user must answer before the report is executed. The information that a business user enters then determines what appears in the resulting report.

Parameter fields offer distinct advantages in allowing business users of the reports to select (or enter) values that, in turn, populate report objects. These values can be used to define the report sort order or to update some type of textual content within the report, such as the report title, description, author name, or otherwise. In this way, the parameter value is having only cosmetic implications on the appearance of the report and not directly impacting the actual data set within the report.

Perhaps the greatest benefit of parameter fields for report designers is the opportunity to have one single report service a very large audience, while empowering the business users of reports to personalize information they are requesting within the report. In this way, parameter fields can be used in coordination with record selections so that a single report can be segmented many different ways. Parameter values that business users enter can be used within record selection formulas to determine what data is retrieved from the database.

For example, consider a Worldwide Sales Report for a large organization. This report could potentially include a tremendous amount of data. Not only is the report itself large, but also many of the business users are not concerned with the entire worldwide scope of the sales data. Rather than allow each salesperson to generate the report to include worldwide data, a parameter dialog can be used to ask the salesperson to select from a list of available countries as shown in Figure 12.1. The report would then return the results for only these specific countries. Thus, by using a parameter field to allow the salespeople to select from a list of countries, the report becomes more valuable for the business users while also limiting the scope of the query by using the selected parameter value(s) to filter the report and reduce the volume of data retrieved.

Figure 12.1. Prompts allow business users to select values to populate the parameter field.