Question

我有两个不同的表，表1和表2.

Table 1
-----------
Resource
Start Date
End date
Total Hours

Table 2
------------
Resource 
Reource type
Total Hours

在这里，我必须根据资源匹配每个表的总小时数，然后必须找到不匹配的数据，并找出与不匹配数据的值的差异。

Answer 1

SELECT [Table 1].[Resource], 
       ([Table 1].[Total Hours] - [Table 2].[Total Hours]) As Difference 
FROM [Table 1]
INNER JOIN [Table 2]
  ON [Table 1].[Resource] = [Table 2].[Resource] 
WHERE [Table 1].[Total Hours] <> [Table 2].[Total Hours]

如果我理解正确，这将为您提供总小时数及其所属资源的差异。括号是必要的，因为列名和表名都很糟糕。

Answer 2

也许[Resource]不是Table1中的唯一键。所以我们需要一些group by子句：

SELECT Resource,SUM([Total Hours]) As SumHours1
INTO #SumHours1
FROM [Table 1] 
GROUP BY [Resource];

SELECT Resource,SUM([Total Hours]) As SumHours2
INTO #SumHours2
FROM [Table 2] 
GROUP BY [Resource];

SELECT Resource,SumHours1,SumHours2
FROM #SumHours1 LEFT OUTER JOIN #SumHours2
ON #SumHours1.Resource=#SumHours2.Resource

在MS Access中，必须比较两个不同表中的值，并找出值之间的差异？

2 个答案: