如题。
$fields = "M.order_number,M.uuid,N.product_name";
$orditems_mod = M('mall_orders as M','mi_','API');
$orderlist = $orditems_mod
->join('LEFT JOIN (SELECT order_number,product_name FROM mi_mall_order_items GROUP BY order_number,product_name) N ON N.order_number = M.order_number')
->where($where)
->field($fields)
->select();
提示：SQLSTATE[42S22]: Column not found: 1054 Unknown column 'M.order_number' in 'field list'"
是不支持这种写法，还是哪里有问题啊。