$total = db('express_info')
->alias('e')
->join('order_info o', 'o.pay_id=e.pay_id', 'LEFT')
->join('admin admin', 'admin.id=e.admin_id', 'LEFT')
->where($where)
->order($sort, $order)
->count();
$list = db('express_info')
->alias('e')
->join('order_info o', 'o.pay_id=e.pay_id', 'LEFT')
->join('admin admin', 'admin.id=e.admin_id', 'LEFT')
->field('e.distributor,e.number,e.freight,e.delivery_price,e.payment,e.pay_id,e.remark,e.updated_at,admin.nickname,o.created_at,e.goods_name')
->where($where)
->order($sort, $order)
->limit($offset, $limit)
->select();
当条件不是主表字段的时候查询表的别名会失效。