DEDECMS怎么获取当前栏目及所有子栏目的文章数量

/* 
* 返回符合记录的文章数量 
* @description DEDE不允许执行子查询，解决栏目下文章统计的问题 
* @param $level 为真时查询所有子类目 
* */ 
function getTotalArcByTid($tid, $level=TRUE) { 
global $dsql; 
$level==TRUE && $tid = GetSonTypeID($tid); 
$sql = "SELECT count(id) as total from `dede_archives` where typeid in($tid)"; 
$result = $dsql->GetOne($sql); 
return $result['total']; 
} 
/* 
* 递归获取符合条件的子栏目 
* @param $tid 栏目ID 
* @return string 
* */ 
function GetSonTypeID($tid) 
{ 
global $dsql; 
$dsql->SetQuery("Select id From `dede_arctype` where reid in($tid) And ishidden<>1 order by sortrank"); 
$dsql->Execute($tid); 
$typeid = ''; 
while($row=$dsql->GetObject($tid)) 
{ 
$typeid .= "{$row->id},"; 
$typeid .= GetSonTypeID($row->id); 
} 
return trim($typeid,','); 
}