The SQL translation of that Cyrstal Syntax would be to use an SQL Case statement like this:
Code:
Case 
  when TABLENAME.FIELDNAME1 = @PAR1@ Then TABLENAME.FIELDNAME1
  when TABLENAME.FIELDNAME2 = @PAR1@ Then TABLENAME.FIELDNAME2
  when TABLENAME.FIELDNAME3 = @PAR1@ Then TABLENAME.FIELDNAME3
  ELSE ''
End
as Some_Output_Column_Name
The "Else" is optional, but if no condition is satisfied, usually a good idea in order to avoid a null value as the result.

Dynamic AI supports up to 10 @PAR#@ replaceable parameters. When data type is character then the parameter must be enclosed in single quotes in the SQL.

At runtime Dynamic AI will generate a UI object to prompt the user for a value -- which can have a default specified in the view.

You would typically use parameters inside sub-queries in a dynamic view.

Bob