当我运行我的查询时，聚合函数异常

Question

这是我以前的问题（Getting an exception with datetime diff）的扩展，但是这次我将我的totalbreaktime设置为float，下面是我的新查询。

MERGE Time_Tracker as target using (SELECT USERID, cast(DATEDIFF(second,starttime,endtime)/60.0 as numeric(36,2)) as ColumnWithBreaksCount FROM BreaksTable 
where CONVERT(Date, StartTime) = CONVERT(Date, GETDATE()) GROUP BY USERID) as source ON target.USERID = source.USERID 
WHEN MATCHED THEN UPDATE SET BREAKS = source.ColumnWithBreaksCount; 

这次当我运行这个查询时，我得到了下面的异常。

Msg 8120, Level 16, State 1, Line 1 
Column 'BreaksTable.StartTime' is invalid in the select list because it is not contained in either an aggregate function or the GROUP BY clause. 
Msg 8120, Level 16, State 1, Line 1 
Column 'BreaksTable.EndTime' is invalid in the select list because it is not contained in either an aggregate function or the GROUP BY clause. 

问题：

1. 正如我前面的问题的讨论，我想更新我的Time_tracker.breaks作为基于日期breakstable.totalbreaktime的总和。
2. 当我运行查询（前一个）时，它正在考虑所有数据而不是当前日期的数据。

而我的表格数据如下。

Time_Tracker

BreaksTable

请让我知道我要去哪里错了，我怎么能解决这个问题。

感谢

Answer 1

你有这样的子查询中查询：

SELECT USERID, 
     cast(DATEDIFF(second, starttime, endtime)/60.0 as numeric(36,2)) as ColumnWithBreaksCount 
FROM BreaksTable 
WHERE CONVERT(Date, StartTime) = CONVERT(Date, GETDATE()) 
GROUP BY USERID; 

第二列是不是一个集合列，也不是在GROUP BY子句中的表达式中的列。因此错误。

我可以推测你真正想要的第二列SUM()：

MERGE Time_Tracker as target using 
     (SELECT USERID, 
       cast(SUM(DATEDIFF(second, starttime, endtime))/60.0 as numeric(36,2)) as ColumnWithBreaksCount 
     FROM BreaksTable 
     WHERE CONVERT(Date, StartTime) = CONVERT(Date, GETDATE()) 
     GROUP BY USERID 
    ) as source 
     ON target.USERID = source.USERID 
WHEN MATCHED THEN UPDATE SET BREAKS = source.ColumnWithBreaksCount;