基于COUNT的过滤行为很奇怪

Question

我正在处理一个查询，该查询显示具有多个ActivityDate，TaskId和EnteredBy重复项的行：

SELECT t1.*
FROM [DailyTaskHours] t1
INNER JOIN (
    SELECT ActivityDate
        ,taskId
        ,EnteredBy
    FROM [DailyTaskHours]
    GROUP BY EnteredBy
        ,taskId
        ,ActivityDate
    HAVING COUNT(*) > 1
    ) t2 ON (
        t1.ActivityDate = t2.ActivityDate
        AND t1.taskId = t2.taskId
        AND t1.EnteredBy = t2.EnteredBy
        AND t1.Hours != 0
        )
ORDER BY TaskId

它看起来几乎正常，但有一个异常现象：

即使视图中只有1个taskId，也会返回上面突出显示的行（2732）。如果有＆gt;我只希望它返回1个重复的TaskId。

我做错了什么？

编辑请求选择：

SELECT ActivityDate ,taskId ,EnteredBy FROM [DailyTaskHours] where TaskId = 2732 

^这解释了它出现的原因，但为什么这两个10/22条目都没出现？

Answer 1

您的联接过滤器t1.hours != 0，但您的子查询（t2）没有相同的过滤器。像这样添加它：

SELECT t1.*
FROM [DailyTaskHours] t1
INNER JOIN (
    SELECT ActivityDate
       ,taskId
       ,EnteredBy
    FROM [DailyTaskHours]
    WHERE hours != 0
    GROUP BY EnteredBy
       ,taskId
       ,ActivityDate
    HAVING COUNT(*) > 1
    ) t2 ON (
       t1.ActivityDate = t2.ActivityDate
       AND t1.taskId = t2.taskId
       AND t1.EnteredBy = t2.EnteredBy
       AND t1.Hours != 0
       )
ORDER BY TaskId