Warning:mysql_fetch_assoc()expectsparameter一toberesource

Warning: mysql_fetch_assoc() expects parameter 1 to be resource,
Warning: mysql_fetch_assoc() expects parameter 1 to be resource,报错

function UpdateDeliveryNumber($number){
    
    $sql=new MYSQL();
    $n_qz=$number.date("md");
	$head=str_pad($n_qz,12,0);
    
       $sqlstr="SELECT group_concat(`order_id`) FROM `Sale_Order` “;
       $sqlstr.="WHERE `number`=$number GROUP BY `recipient_name`,`ship_address`,`delivery_area`"; 
       $sqlstr.="ORDER BY length(group_concat(`order_id`)) DESC  ";
	$query=$sql->query($sqlstr);
    echo $sqlstr."
";
    echo $sql->num_rows($query)."
";
    if($sql->num_rows($query)){//判断是否查询到记录
	 while($rs=$sql->fetch_array($query)){
	 echo "select OK";
	$sql_item="UPDATE `Sale_Order` SET `delivery_number`='$head' WHERE `order_id`='' ";
	$order_item_id=explode(",",$rs["group_concat(`order_id`)"]);
        echo $rs["group_concat(`order_id`)"]."
";
	foreach($order_item_id as $n)
		{
			$sql_item.=" OR `order_id`='$n'  ";
		}
        echo $head."
";
	$head++;
        echo $sql_item."
";
        $query_item=$sql->query($sql_item);
	echo $query_item;
    	}
        }
    }

UpdateDeliveryNumber(21);
echo "OK";

SELECT group_concat(`order_id`) FROM `Sale_Order` WHERE `number`=21 GROUP BY `recipient_name`,`ship_address`,`delivery_area` ORDER BY length(group_concat(`order_id`)) DESC
2
select OK114-4278868-5227463
210323000000
UPDATE `Sale_Order` SET `delivery_number`='210323000000' WHERE `order_id`='' OR `order_id`='114-4278868-5227463'
Warning: mysql_fetch_assoc() expects parameter 1 to be resource, boolean given in /var/www/html/demo/class/mysql.class.php on line 53 OK

请问哪里有问题啊，语句都拿去phpmyadmin执行过了，都是正常的

------解决思路----------------------
你的 MYSQL 类封装的有问题
------解决思路----------------------
把你的类贴出来以供分析