复杂的MySQL查询，变人口

Question

我与列的表：

AnswerID，OwnerUserID，CreationDate

如何填充标题（AnswersPosted）与总人数的答案是OwnerUserID有第四列发布到为该AnswerID列出的CreationDate？

编辑：

下面是一个表应该看起来像什么样子的例子。 （对不起，自从我刚刚加入后，我无法发布图片...）我很想让最后一列显示所有正确的数字。谢谢！

Answer 1

使用此解决方案：

SELECT a.AnswerID, 
     a.OwnerUserID, 
     a.CreationDate, 
     b.cnt AS AnswersPosted 
FROM tbl a 
JOIN (
     SELECT a.OwnerUserID, 
       a.CreationDate, 
       COUNT(b.OwnerUserID) AS cnt 
     FROM  tbl a 
     LEFT JOIN tbl b ON a.OwnerUserID = b.OwnerUserID 
         AND b.CreationDate < a.CreationDate 
     GROUP BY a.OwnerUserID, 
       a.CreationDate 
     ) b ON a.OwnerUserID = b.OwnerUserID 
      AND a.CreationDate = b.CreationDate 

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