SubjectsAll dynamic prompt for Crystal

The prompt group 'RDS SubjAll M' in Crystal Reports requires logic in the Record Selection formula to account for the ' All' value for all subjects. Below is an example of how to construct the query:

if ({?Subject} <> " All") then 

({?Subject} = {RDS_CLASS_VW.CLASS_SUBJECT_CD} and

{?Institution} = {RDS_CLASS_VW.CLASS_INSTITUTION_CD})

else

{?Institution} = {RDS_CLASS_VW.CLASS_INSTITUTION_CD}

If the Subject parameter equals ' All' we simply ignore it.