Aggregates and Search Parameters

In V9, how do you construct an aggregate that contains the equivalent of the V8-style search parameter (i.e. if Null it's ignores, else it's used)? 
Hi Gerry,

You can achieve that the same way your SimpleQueries with that feature turn out when upgraded which is to use the following pattern (considering the AttributeX :

(ParameterX = Nullidentifier()) or (Entity.AttributeX = ParameterX)

Hope this helps