public RdbmsLiteral getRdbmsLiteral(Number num, String label, String language,
String datatype) {
Number id = ids.idOf(num);
if (datatype == null && language == null)
return new RdbmsLiteral(id, literals.getIdVersion(), vf.createLiteral(label), null);
if (datatype == null)
return new RdbmsLiteral(id, literals.getIdVersion(), vf.createLiteral(label, language), null);
return new RdbmsLiteral(id, literals.getIdVersion(), vf.createLiteral(label, vf.createURI(datatype)), null);
}