I have a report and a subreport in SSRS 2008 that, independent of one another, run in about one second. However, when I link the subreport into the main report, it doesn't want to seem to come back. I've stopped it after a few minutes, so I don't know if eventually it would come back or not. I suspect it could be a parameter issue; specifically that I just don't know what I'm doing :)
My main report has one Dataset that returns multiple student rows that are displayed in a standard report table - one row per student. In one of the table cells, I have placed the subreport. Both reports are in the same project, so I select SubReport Properties and go through the following steps to hook them up:
1. Under the General section, I select the name of the subreport to use from "Use this report as a subreport"
2. Under the Parameters section, I Add a parameter, select the parameter name in the first drop-down box (the subreport only has one parameter, a studentID), and fromt he Value dropdown box, I select StudentID, which is a field in the Main Subreport.
When I run the report, it takes forever. If I go back into the Subreport Preperties and back to the Parameters section, and click on the Expression box, I notice that my expression: =Fields!StudentID.Value, is underlined in red. When I place the mouse cursor over top of it, it says: Unknown Collection Member. Also, down in the Category box, if I select Fields, no items are listed and the description says: Report item not linked to a dataset.
Does this mean I am not connecting the two reports properly?