WhereNull is a WhereExpression subclass with a just a
null in it. This object has no members besides the one exposed by WhereExpression. This is used in where expressions like
fieldname is null, the
null would be represented by a WhereNull object.
Where expressions are used to filter a request by applying extra conditions. It's generally are stored as an xml formatted string, however the scripting implementation can unwrap these in a tree. The WhereBuilder object can be used to create new instances of these objects.
The code snippet below shows, how WhereNull Object can be created:
var VarNull = WhereBuilder.createNull();