我需要使用 sql 查询根据订单 ID 获取最后创建的合格骑手 ID 和 ping 骑手 ID

Question

我需要把我的数据集作为这个表

我正在尝试获得这样的合格集，还需要 group_concat ping 集

x.id IN (SELECT MAX(x.id) FROM x WHERE ping rider id IS NULL GROUP BY orderId)

Answer 1

您可以根据eligible_riders 中非空值的累积数量来分配组。然后聚合并取最后一个值：

select og.*
from (select order_id, grp, max(eligible_riders) as eligible_riders,
             group_concat(rider_id) as riders,
             row_number() over (partition by order_id order by min(id) desc) as seqnum
      from (select t.*,
                   sum(eligible_riders <> '') over (partition by order_id order by id) as grp
            from t
           ) t
      group by order_id, grp
     ) og
where seqnum = 1;

嗯。 . .您也可以使用相关子查询来执行此操作，这可能看起来更简单一些：

select order_id, max(eligible_riders) as eligible_riders,
       group_concat(rider_id) as riders
from t
where t.id >= (select max(t2.id)
               from t t2
               where t2.order_id = t.order_id and
                     t2.eligible_riders <> ''
              )
group by order_id;

为了提高性能，您需要在(order_id, eligible_riders) 上建立索引。