如何计算dataexplorer中每个帖子中最常见的CloseReasonTypes数？

Question

我开始撰写这个查询，我发现很难理解为什么要结束这个问题。

select
   TOP ##Limit:int?38369## -- The maximum value the hardware can handle.
   Posts.Id as [Post Link], -- Question title.
   Count(PendingFlags.PostId) as [Number of pending flags], -- Number of pending flags per questions.
   Posts.OwnerUserId as [User Link], -- Let click on the colum to see if the same user ask off-topic questions often.
   Reputation as [User Reputation], -- Interesting to see that such questions are sometimes asked by high rep users.
   Posts.Score as [Votes], -- Interesting to see that some questions have more than 100 upvotes.
   Posts.AnswerCount as [Number of Answers], -- I thought we shouldn't answer on off-  topic post.
   Posts.FavoriteCount as [Number of Stars], -- Some questions seems to be very helpfull :) .
   Posts.CreationDate as [Asked on], -- The older is the question, the more is the chance that flags on them can't get reviewed.
   Posts.LastActivityDate as [last activity], -- Similar effect as with Posts.CreationDate.
   Posts.LastEditDate as [modified on],
   Posts.ViewCount
from posts
   LEFT OUTER JOIN Users on Users.id = posts.OwnerUserId
   INNER JOIN PendingFlags on PendingFlags.PostId = Posts.Id
where ClosedDate IS NULL -- The question is not closed.
group by Posts.id, Posts.OwnerUserId, Reputation, Posts.Score, Posts.FavoriteCount, Posts.AnswerCount, Posts.CreationDate, Posts.LastActivityDate, Posts.LastEditDate, Posts.ViewCount
order by Count(PendingFlags.PostId) desc; -- Questions with more flags have more chance to get them handled, and the higher is the probabilty that the question is off-topic (since several users already reviewed the question).

考虑到每个问题都有几个标志，我不能使用一个简单的表来显示每个标志使用的原因，但我认为它应该与每个帖子最常见的CloseReasonTypes.Id值相关:这就引出了两个问题：

• First：在查看这个查询之后，我应该加入CloseReasonTypes to PendingFlags，以显示原因名而不是它们的编号。由于Posts和PendingFlags之间没有共同的字段，但是由于我使用from posts作为连接表的基础，所以我不知道如何进行这个连接。
• Secound：我不知道在每一行中选择最常用的关闭原因。虽然有几个问题似乎已经讨论过类似的情况，但我不能使用他们的答案，因为他们询问如何在整个表上找到最常见的值，从而生成一个只有一列和一行的表，而我需要对每个帖子上的标志计数。

Answer 1

虽然不完全是你想要的，但我相信这个查询会给你一个好的开始。

select
    PostId as [Post Link], 
    duplicate = sum(case when closereasontypeid = 101 then 1 else 0 end), 
    offtopic = sum(case when closereasontypeid = 102 then 1 else 0 end),
    unclear = sum(case when closereasontypeid = 103 then 1 else 0 end),
    toobroad = sum(case when closereasontypeid = 104 then 1 else 0 end),
    opinion = sum(case when closereasontypeid = 105 then 1 else 0 end),
    ot_superuser = sum(case when CloseAsOffTopicReasonTypeId = 4 then 1 else 0 end),
    ot_findexternal = sum(case when CloseAsOffTopicReasonTypeId = 8 then 1 else 0 end),
    ot_serverfault = sum(case when CloseAsOffTopicReasonTypeId = 7 then 1 else 0 end),
    ot_lackinfo = sum(case when CloseAsOffTopicReasonTypeId = 12 then 1 else 0 end),
    ot_typo = sum(case when CloseAsOffTopicReasonTypeId = 11 then 1 else 0 end)
from pendingflags
where 
    flagtypeid in (13,14)   -- Close flags
    and creationdate > '2014-04-15'
group by PostId

这仅仅是看今年4月15日以来关闭的邮件，并返回了大约23500个记录。

我认为数据资源管理器不包含已删除的帖子，因此这些帖子不包含在结果中。

如果/当添加或删除新的关闭原因时，这将需要修改。