my$sql="select xref.accession, xref.label, xref.version, xref.description from xref, source where xref.source_id = source.source_id and source.name like 'RefSeq_%RNA'";
my$sql="select xref.accession, xref.label, xref.version, xref.description from xref, source where xref.source_id = source.source_id and source.name = ?";