User`s guide

22.4 Linking a subreport to the main report without modifying the selection formula
Crystal Reports uses a parameter field mechanism for linking subreports to main reports.
When linking a main report field that is not a parameter field to a subreport field, the program:
• Automatically creates a parameter field to complete the link.
• Modifies the subreport record selection formula to select those records in which the subreport field
is equal to the parameter field value.
The need for a parameter field is implied; it is called an "Implicit Link" situation.
At times, you may wish to use a linked parameter field in a subreport without using it as part of the
selection formula for the subreport. For instance, you may want the main report to pass in a summary
value that can be used in calculations by the subreport, or you may want the main report to pass in the
title of the subreport.
When you link a field in the main report to a parameter field that you have created in the subreport, the
program:
• Checks the link you have specified.
• Does not create any additional parameter fields.
• Does not modify the subreport record selection formula.
Specifying a link is called an "Explicit Link" situation.
22.4.1 To link a subreport to a main report without modifying the selection formula
1.
Create a parameter field in the subreport.
2.
Link a field in the main report to that parameter field.
22.5 Combining unrelated reports by using subreports
At times, you may wish to combine unrelated reports into a single report. For example, you may want
to create a single report that presents:
• Sales grouped by sales representative.
• Sales grouped by item.
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Subreports