根据当前id查子级id 祖先查后代

function inquireID1($cate_id){//返回数据会一直叠加

static $arrr= [];//静态变量
    $sql = "select id,cate_name,pid from category where pid=$cate_id";
    $rows = getAll($sql);
    if ($rows){
        foreach ($rows as $v ){
            $arrr[]=$v['id'];
            //递归查询
            inquireID1($v['id']);
        }
    }
    return $arrr;
}

function inquireID2($cate_id,&$arrr){返回数据不会叠加
    $sql = "select id,cate_name,pid from category where pid=$cate_id";
    $rows = getAll($sql);
    if ($rows){
        foreach ($rows as $v ){
            $arrr[]=$v['id'];
            //递归查询
            inquireID2($v['id'],$arrr);
        }
    }
    return $arrr;
}