true prefix oplsioc: prefix sioc: prefix foaf: select (bif:LEFT (?cust+>tpch:phone, 2)) as ?cntrycode, (count (1)) as ?numcust, sum (?cust+>tpch:acctbal) as ?totacctbal from where { { select (avg (?cust2+>tpch:acctbal)) as ?acctbal_threshold where { ?cust2 a tpch:customer . filter ((?cust2+>tpch:acctbal > 0.00) && bif:LEFT (?cust2+>tpch:phone, 2) in ("13", "35", "31", "23", "29", "30", "17", "18") ) } } ?cust a tpch:customer . optional { select ?cust (count(?ord)) as ?ord_cnt where { ?cust a tpch:customer ; tpch:customer_of ?ord } } filter ((?cust+>tpch:acctbal > ?acctbal_threshold) && bif:LEFT (?cust+>tpch:phone, 2) in ("13", "35", "31", "23", "29", "30", "17", "18") && !bound (?ord_cnt) ) } order by (bif:LEFT (?cust+>tpch:phone, 2)) ]]>http://demo.openlinksw.com/tpchsoft/sparql