Crystal Report with multiple datasources, one is empty - crystal-reports

Question

I have a Crystal report with a table as a datasource and I want to include another table with details for the report footer.
I have two data sources in the report which are not linked, but when the selection criteria returns no rows from the main table, the results from the non-empty non-linked source are also empty.
I suspect it's doing a cross join between the two datasources, so if one is empty, that joined with another is also empty. The problem is I need my rows from the non-empty table to show in the report footer section, and they're getting suppressed by the other, empty datasource.
How can I get rows from an independent table to show in the report footer when the selection criteria and their parameter choices return an empty result set in the main table?
Thanks for your help,
-Beth
Also, I tried using a command as a datasource with sql like this:
select * from waitlist
union all
select distinct null as reportID, null as ..., lastupdated
from waitlist
but it still returns null for lastupdated and suppresses the subreport in the report footer.

Answer 1

I ended up setting my report datasource to a view which unioned another row to the table. I also needed to change my selection criteria so it allows this row to pass through.
Here's my datasource:
CREATE VIEW [dbo].[vw_rpt_waitlist] AS
select * from waitlist
union all
select distinct
reportID,
null as (fields...),
lastupdated,
'reserved' as countyName
from
waitlist
and here's my record selection formula:
({vw_rpt_waitlist.countyName} = {?County} or
{vw_rpt_waitlist.countyName} = "reserved") and
{vw_rpt_waitlist.reportID} = 14
I'm also suppressing the detail section if there were real rows returned:
formula = {vw_rpt_waitlist.countyName} = "reserved"
and to get the parameterized county name they selected in the page header of the report, I'm using:
dim t as string
dim c as string
if {vw_rpt_waitlist.countyName}="reserved" then
c = {?County}(1)
else
c = {vw_rpt_waitlist.countyName}
end if
t = "Waitlist by " + {#serviceTitle} + " and Waiver Need Index as of "
+ cstr({vw_rpt_waitlist.lastUpdated},"MM/dd/yyyy")
formula = t
Since the 'reserved' county always comes through, the subreports are not suppressed.