Suppose I have an input control that controls the value of a parameter that is referenced in a WHERE SQL clause, that can be either defined or not defined. Is that possible? In other words, suppose I have a SQL query that references $P{something}, but if $P{something} is undefined, I want the SQL WHERE part to be ignored. Perhaps I'm doing this the wrong way, but is it possible to put a condition somewhere that checks whether the parameter is defined before the SQL query is executed?