SSRS count of rows within each group

Question

I have a report that will show several groups of details records on the page. I would like to order them so that the groups with more rows are first. Does anyone know what formula should show me the details row count per group? I tried =CountRows(MainGroup) but that errored.

Answer 1

If you include a scope name in any expression, it has to be enclosed in quotes and is case sensitive, so in your case it's just a case of adding the quotes...

=CountRows("MainGroup")

Note: If the expression sits in the "MainGroup" row(s) anyway, then there is no need to specify the scope so =CountRows() would return the same results as when no scope is specified, the current scope is used.