SQL calculation in expression editor CR 2008

Question

This SQL expression works on MS SQL Server 2005 but not in the SQL Expression Editor of Crystal Reports.
Why? Any alternatives?
declare @Trash Decimal
declare @Done Decimal
set @Trash =
  select count(*) from dbo.NL_NM_NUON
  WHERE MAN_CAMPAIGNNAME = '9.304_Winback TM CM Jan 2010 - Bosch'  AND
    fldFormalities In ('Persoon is verhuisd', 'Adres matcht niet met telefoonnummer',
         'Weigering Gesprek', 'Dubbel in bestand', 'Persoon overleden',
         'Beslisser tijdens actieperiode afwezig')
    OR
    fldEndresult = 'Is sinds kort klant bij NUON'
set @Done =
  select count(*) from
  NL_NM_NUON Where
  NL_NM_NUON.MAN_CAMPAIGNNAME = '9.304_Winback TM CM Jan 2010 - Bosch' AND
  STATUS IN ('U','F')
Select (@Trash / @Done) * 100
Edited by: Valmont on Feb 10, 2010 2:36 PM

Answer 1

Create two different sql expressions like this
%Expression1:
  select count(*) from dbo.NL_NM_NUON
  WHERE MAN_CAMPAIGNNAME = '9.304_Winback TM CM Jan 2010 - Bosch'  AND
    fldFormalities In ('Persoon is verhuisd', 'Adres matcht niet met telefoonnummer',
         'Weigering Gesprek', 'Dubbel in bestand', 'Persoon overleden',
         'Beslisser tijdens actieperiode afwezig')
    OR
    fldEndresult = 'Is sinds kort klant bij NUON'
%Expression2:
  select count(*) from
  NL_NM_NUON Where
  NL_NM_NUON.MAN_CAMPAIGNNAME = '9.304_Winback TM CM Jan 2010 - Bosch' AND
  STATUS IN ('U','F')
Now Create a formula like this
({%Expression1}/{%Expression2})*100
HTH
Raghavendra.G