Question

我在尝试找出以下问题时遇到了问题，甚至不能100％确定是否可以单独从纯mysql查询完成此任务。

我需要选择共享相同ID和类型的行，同时跟踪他们的TimeStamps。

SELECT ObjectId, TimeStamp, Count(ObjectId) As theCount FROM 
   (Select ObjectId, TimeStamp, RelationType, ObjectType From Table
      Group By ObjectId, TimeStamp) As tmp
      WHERE RelationType = 'A'
      AND ObjectType = 'B'
      GROUP By ObjectId
      HAVING Count(ObjectId) >= 0 ORDER By theCount DESC

查找和计算足够类似的行数供我选择的部分很容易，但我在下一部分遇到了麻烦。

我需要在中位数TimeStamp之后跟踪所有TimeStamps，并获得高于中位数TimeStamp的那些TimeStamps的平均值。我需要将那些TimeStamps的平均值高于其中位数，以便我可以命令它们进行DESC。

如果我的问题不够明确或有任何问题请发帖，我可以回复评论。我花了很多时间尝试不同的方法来实现我的目标，但我觉得唯一正确的代码是上面发布的查询。

以下代码就是我现在所处的位置。我得到了所有分组项目的平均值，但就像我说我只需要在组中位数之上的TimeStamps的平均值。

SELECT * FROM( SELECT ObjectId, PostDate, Count(ObjectId) AS Count, AVG(TimeStamp) AS Average
   FROM (Select ObjectId, TimeStamp, RelationType, ObjectType 
      FROM Relations Group By ObjectId, TimeStamp
   ) As tmp
WHERE RelationType = 'A' AND ObjectType = 'B'
GROUP By ObjectId HAVING Count(ObjectId) >= 1
AND AVG(TimeStamp) > MIN(TimeStamp)
ORDER By Count DESC ) AS tmp2 ORDER BY Average DESC, Count LIMIT 10

            RETURNS:

            ObjectId: 112717 // Count: 2 // Average: 20151030188390.5
            ObjectId: 166047 // Count: 4 // Average: 20151023363026.25
            ObjectId: 166312 // Count: 3 // Average: 20151022171454.332
            ObjectId: 166309 // Count: 2 // Average: 20151022170765.5
            ObjectId: 166307 // Count: 2 // Average: 20151022170765.5
            ObjectId: 165163 // Count: 2 // Average: 20151021188390.5
            ObjectId: 133214 // Count: 2 // Average: 20151021188388
            ObjectId: 165164 // Count: 2 // Average: 20151021188388
            ObjectId: 165831 // Count: 2 // Average: 20151021184532.5
            ObjectId: 165822 // Count: 2 // Average: 20151021184532.5

MySQL查询关于组中平均大于中位数的行

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