MySQL server error report:Array
(
    [0] => Array
        (
            [message] => MySQL Query Error
        )

    [1] => Array
        (
            [sql] => SELECT g.goods_id,goods_name,shop_price,goods_thumb,cat_id,url_name,url_name as url_defined,brand_id,supplier_id,g.goods_sn,g.market_price0 as market_price , RAND() AS rnd FROM `mayitao`.`yp_goods_recommend` as gr left join `mayitao`.`yp_items` AS g on g.goods_id = gr.goods_id  WHERE gr.is_best=1 and g.cat_id > 0  order by sort_order asc limit 5
        )

    [2] => Array
        (
            [error] => Column 'sort_order' in order clause is ambiguous
        )

    [3] => Array
        (
            [errno] => 1052
        )

)