SELECT route_no FROM (ClientDataPath+'customer') ; GROUP BY route_no ORDER BY route_no ; INTO CURSOR RouteListAll works well there. However, this does not:
SELECT route_no AS routenum ; FROM (ClientDataPath+'customer') ; WHERE .NOT.EMPTY(route_no) ; UNION ALL ; SELECT route_no2 AS routenum ; FROM (ClientDataPath+'customer') ; WHERE .NOT.EMPTY(route_no2) ; UNION ALL ; SELECT route_no3 AS routenum ; FROM (ClientDataPath+'customer') ; WHERE .NOT.EMPTY(route_no3) ; UNION ALL ; SELECT rr_1 AS routenum ; FROM (ClientDataPath+'customer') ; WHERE .NOT.EMPTY(rr_1) ; UNION ALL ; SELECT rr_2 AS routenum ; FROM (ClientDataPath+'customer') ; WHERE .NOT.EMPTY(rr_2) ; GROUP BY routenum ORDER BY routenum ; INTO CURSOR RouteListAssistance gratefully accepted - apparently I've done something wrong while UNIONing.