M()->table('ecs_attribute a')->join('ecs_goods_attr ga on a.attr_id=ga.attr_id')->join('ecs_goods g on ga.goods_id=g.goods_id')->where("g.is_delete = 0 AND g.is_on_sale = 1 AND g.is_alone_sale = 1 AND a.attr_id='$value'")->find();
通过Model里面把几张表关联起来