MS Access Switch Aggregate Function

Question

我有以下SQL语句。但是，它无法运行。它说：

  

您的查询不包含指定的表达式   'DateValue（开关（小时（[日期时间]）＆gt; = 18和小时（[日期时间]）＆lt; 22，[日期   时间]，小时（[日期时间]）＆gt; = 22，[日期时间]，小时（[日期时间]）＆gt; = 0和   小时（[日期时间]）＆lt; 2，[日期时间]，小时（[日期时间]）＆gt; = 2和小时（[日期]   时间]）＆lt; 6，[日期时间] -1，小时（[日期时间]）＆gt; = 6和小时（[日期]   时间]）＆lt; 10，[日期时间] -1，小时（[日期时间]）＆gt; = 10和小时（[日期]   时间]）＆lt; 14，[日期时间] -1，小时（[日期时间]）＆gt; = 14和小时（[日期]   时间]）＆lt; 18，[日期时间] -1））作为DateValue'作为聚合的一部分   功能

SELECT DateValue(Switch(Hour([Date Time])>=18 And Hour([Date Time])<22,[Date Time],Hour([Date Time])>=22,[Date Time],Hour([Date Time])>=0 And Hour([Date Time])<2,[Date Time],Hour([Date Time])>=2 And Hour([Date Time])<6,[Date Time]-1,Hour([Date Time])>=6 And Hour([Date Time])<10,[Date Time]-1,Hour([Date Time])>=10 And Hour([Date Time])<14,[Date Time]-1,Hour([Date Time])>=14 And Hour([Date Time])<18,[Date Time]-1)) As DateValue, Avg([MFR g/10min]) AS Average, Max([MFR g/10min]) - Min([MFR g/10min]) As Difference
FROM [In process analysis result]
GROUP BY DateValue([Date Time]);

有什么问题吗？

编辑1： 如果我运行以下查询，它将起作用：

SELECT DateValue(Switch(Hour([Date Time])>=18 And Hour([Date Time])<22,[Date Time],Hour([Date Time])>=22,[Date Time],Hour([Date Time])>=0 And Hour([Date Time])<2,[Date Time],Hour([Date Time])>=2 And Hour([Date Time])<6,[Date Time]-1,Hour([Date Time])>=6 And Hour([Date Time])<10,[Date Time]-1,Hour([Date Time])>=10 And Hour([Date Time])<14,[Date Time]-1,Hour([Date Time])>=14 And Hour([Date Time])<18,[Date Time]-1)) AS DateValue, Avg([MFR g/10min]) AS Average, Max([MFR g/10min]) - Min([MFR g/10min]) As Difference FROM [In process analysis result] GROUP BY Switch(Hour([Date Time])>=18 And Hour([Date Time])<22,[Date Time],Hour([Date Time])>=22,[Date Time],Hour([Date Time])>=0 And Hour([Date Time])<2,[Date Time],Hour([Date Time])>=2 And Hour([Date Time])<6,[Date Time]-1,Hour([Date Time])>=6 And Hour([Date Time])<10,[Date Time]-1,Hour([Date Time])>=10 And Hour([Date Time])<14,[Date Time]-1,Hour([Date Time])>=14 And Hour([Date Time])<18,[Date Time]-1);

然而，结果不是我想要的。我想按照列{1}}的日期进行分组：

DateValue（）没有分组，我无法得到最大值和最小值之间的平均值和差值。

请帮忙......

Answer 1

您的分组功能应与选择相同（在您的分组条件中添加：DateValue（））：

SELECT DateValue(Switch(Hour([Date Time])>=18 And Hour([Date Time])<22,[Date Time],Hour([Date Time])>=22,[Date Time],Hour([Date Time])>=0 And Hour([Date Time])<2,[Date Time],Hour([Date Time])>=2 And Hour([Date Time])<6,[Date Time]-1,Hour([Date Time])>=6 And Hour([Date Time])<10,[Date Time]-1,Hour([Date Time])>=10 And Hour([Date Time])<14,[Date Time]-1,Hour([Date Time])>=14 And Hour([Date Time])<18,[Date Time]-1)) AS DateValue, Avg([MFR g/10min]) AS Average, Max([MFR g/10min]) - Min([MFR g/10min]) As Difference FROM [In process analysis result] GROUP BY DateValue(Switch(Hour([Date Time])>=18 And Hour([Date Time])<22,[Date Time],Hour([Date Time])>=22,[Date Time],Hour([Date Time])>=0 And Hour([Date Time])<2,[Date Time],Hour([Date Time])>=2 And Hour([Date Time])<6,[Date Time]-1,Hour([Date Time])>=6 And Hour([Date Time])<10,[Date Time]-1,Hour([Date Time])>=10 And Hour([Date Time])<14,[Date Time]-1,Hour([Date Time])>=14 And Hour([Date Time])<18,[Date Time]-1));