JESS: Query query...

[James O'Brien]

Hi all,   This is a really simple question but one that I'm unable to find the answer to. I'm attempting to use a query to extract one fact from a set of nearly identical ones. The query at the moment looks like :   (defquery find-xmlID     "Finds the xmlID of a fact from a supplied ElementID"     (declare (variables ?elID))     (printout t "searching for xmlID for elID: " ?elID)     (Attribute (ElementID ?elID) (AttributeName "xmlID")))   and some of the facts that it's working on are below. Basically I'm trying to extract f-223 and I'm assuming that I should be doing it the way I am... although that query is returning no results. I've toyed with a syntax of (and ((Attribute (ElementID ?elID)) (AttributeName "xmlID")))) and that wasn't helpful either.   f-230   (MAIN::Attribute (DocumentName "RuleBase") (ElementID 43) (AttributeName "t_ex_t0") (Text "1990")) f-231   (MAIN::Attribute (DocumentName "RuleBase") (ElementID 43) (AttributeName "t_ex_t1") (Text "2000")) f-232   (MAIN::Attribute (DocumentName "RuleBase") (ElementID 43) (AttributeName "type") (Text "DEM")) f-233   (MAIN::Attribute (DocumentName "RuleBase") (ElementID 43) (AttributeName "xmlID") (Text "915"))   any hints to my (probably obvious) error,   regards,   James