查询本体时出现异常

Question

QUERY=" PREFIX table: <http://www.daml.org/2003/01/periodictable/PeriodicTable#> \n"+
            "SELECT ?name ?symbol ?weight ?number \n"+
            "FROM <http://www.daml.org/2003/01/periodictable/PeriodicTable.owl> \n" +
            "WHERE \n" +
            "{ \n"+
            "?uranium table:name \"uranium\". \n"+
            "?uranium table:atomicWeight ?uraniumWeight. \n"+
            "?element table:name ?name. \n"+
            "?element table:symbol ?symbol. \n" +
            "?element table:atomicWeight ?weight. \n" +
            "?element table:atomicNumber ?number. \n" +
            "FILTER ?weight > ?uraniumWeight. \n" +
            "} \n"+
            "ORDER BY ASC[?weight] ";

我在查询periodicTable本体时遇到以下异常异常

线程“AWT-EventQueue-0”com.hp.hpl.jena.query.QueryParseException中的异常：在行遇到“”？weight“” 12，第 8 栏。 期待其中之一： ... ... ... “存在”... 。

Answer 1

您需要在过滤器表达式两边加上括号：

FILTER (?weight > ?uraniumWeight)