Crystal Reports: How to pass a parameter from a subreport to the parent report?

I have a number 开发者_StackOverflow社区of subreports in which I calculate totals. In the main report I need the sum of those totals.

I don't know how to get acces to the totals in the subreports.

You need to look into using Shared Variables, which can be read and written to by both the parent report and its subreports.

Example :

In parent report, a formula to initialise things called 'InitTotal', containing the text :

Shared NumberVar MyTotal := 0;

Place this formula in the report header and suppress it. Add a formula to each subreport called 'AddTotal', containing the text :

Shared NumberVar MyTotal := MyTotal + {FieldToAddToTotal};

Add this formula to the subreport's report footer and suppress it.

Finally, in the report footer of the parent report, add another formula called 'DisplayTotal' containing just the text :

Shared NumberVar MyTotal;

You may also want to consider using a SQL Expression field. It generates a sub-query of sorts in the 'main' query's SELECT clause. As a result, the sub-query must return a scalar value. You can also correlate the sub-query with the main query.

SQL Express fields can also be used in the record-selection formula and will be passed to the database for processing.

See Crystal Reports: Using SQL Expression Fields for more details.