SQL：为其他列中的每个唯一实体提取与列的最大值相关的行段

我有“输入表”，如所附快照所示。 使用SQL，我打算构建一个“输出表”，其中： “MaxDays”：应显示给定“ID”的最大“天”值
“Type_MaxDays”：是与为“MaxDays”标识的最大“Days”相关的“Type”的对应值 “TotalUniqueType”：统计任何给定ID的所有唯一“Type”

例如，对于ID=878，Days=90是（63、90、33、48）的最大值，它对应于Type=A。因此，在输出表中，Max_Days=90，Type_MaxDays=A。由于ID=878总共有4个唯一的“Type”（即A、B、C、D），所以TotalUniqueType=4

查找“TotalUniqueType”似乎很简单，但是来自python/pandas的背景，我不知道如何使用SQL检索“MaxDays”和“Type_MaxDays”。请告知

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一个选项是加入子查询，该子查询为每个

ID

查找最大天数以及不同类型计数。然后，还要选择具有最大天数的行的类型

SELECT
    t1.ID,
    t1.Days AS MaxDays,
    t1.Type AS Type_MaxDays,
    t2.TypeCnt AS TotalUniqueType
FROM yourTable t1
INNER JOIN
(
    SELECT ID, MAX(Days) AS MaxDays, COUNT(DISTINCT Type) AS TypeCnt
    FROM yourTable
    GROUP BY ID
) t2
    ON t1.ID = t2.ID AND t1.Days = t2.MaxDays;

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一个选项是加入子查询，该子查询为每个

ID

查找最大天数以及不同类型计数。然后，还要选择具有最大天数的行的类型

SELECT
    t1.ID,
    t1.Days AS MaxDays,
    t1.Type AS Type_MaxDays,
    t2.TypeCnt AS TotalUniqueType
FROM yourTable t1
INNER JOIN
(
    SELECT ID, MAX(Days) AS MaxDays, COUNT(DISTINCT Type) AS TypeCnt
    FROM yourTable
    GROUP BY ID
) t2
    ON t1.ID = t2.ID AND t1.Days = t2.MaxDays;

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我建议使用窗口功能和聚合：

select id,
       max(days) as maxdays,
       max(case when seqnum = 1 then type end) as type_at_maxdays,
       count(distinct type)
from (select t.*,
             row_number() over (partition by id order by days desc) as seqnum
      from t
     ) t
group by id;

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我建议使用窗口函数和聚合：

select id,
       max(days) as maxdays,
       max(case when seqnum = 1 then type end) as type_at_maxdays,
       count(distinct type)
from (select t.*,
             row_number() over (partition by id order by days desc) as seqnum
      from t
     ) t
group by id;