Do you want to select Record IDs that have a max value between 2 param dates?
Group on Record ID
Insert a Summary Function (Sigma Sign) as:
Field to summarize=Date field
Calculate as Maximum
Summary Location=Group1 footer (record ID footer)
YOu can suppress this field but you need it for the select expert.
Add your 2 date params (?Start Date and ?End Date in this example)
go to your select expert
Hit show formula
Make sure "Group selection" is toggled on
Click on formula editor
Find the MAXIMUM Summary field in your Report Fields and double click it to move it to the formula window
add your date params to the formula so it will end up somehing like:
MAXIMUM({table.datefield},{table.RecordID}) in {?Start Date} to {?End Date}
Is that what you wanted?
NOTE if you have a group tree on you will still see IDs appear there that are now exclude in the body of the report. Group selection process occurs at a different point in the data reading than record selction process.
Edited by DBlank - 03 Dec 2009 at 12:33pm