织梦判断导航二级栏目为空不显示方法

{dede:channelartlist typeid='top'}
{dede:field name='typename'/}
{dede:php}
$id = $refObj->Fields['id'];
$sql = ("SELECt * FROM dede_arctype where reid ='$id'");
$db->SetQuery($sql);
$db->Execute();
if($db->GetTotalRow()){
echo '
';
while($row = $db->GetArray()){
$url = str_replace('{cmspath}','',($row[typedir]));
echo "
".($row[typename])."
";
};
echo '
';
};
{/dede:php}

{/dede:channelartlist}