选择“访问权限不同"?语法错误 [英] Select Distinct in Access? Syntax error

问题描述

我有这个SQL:

SELECT (Min(Time_In) & " to " & Max(Time_Out)) AS [Week Of],
 Round((Sum(DATEDIFF("n", Time_In, Time_Out))/Count(DATEDIFF("n", Time_In, Time_Out))),2) AS [Avg Min of Jog]
FROM SomeTable
WHERE len(Time_In) > 0 AND len(Time_Out) > 0 
AND #01/01/2012# <= Time_In AND #12/31/2012# >= Time_In
GROUP BY DatePart('ww',Time_In);

选择每周慢跑的平均时间.我还想统计一下每周跑步的次数，我试图通过计算jog_id来做到，其中SomeTable对于一个jog_id可能有5个条目.

Which picks out average times of a jog per week. I would also like to include a count how many times jogged per week, which I'm trying to do by counting the jog_id where SomeTable could have 5 entries for one jog_id.

我尝试过:

SELECT (Min(Time_In) & " to " & Max(Time_Out)) AS [Week Of],
 Round((Sum(DATEDIFF("n", Time_In, Time_Out))/Count(DATEDIFF("n", Time_In, Time_Out))),2) AS [Avg Min of Jog],
 Count(distinct jog_id) AS [Num Jogs]
FROM SomeTable
WHERE len(Time_In) > 0 AND len(Time_Out) > 0 
AND #01/01/2012# <= Time_In AND #12/31/2012# >= Time_In
GROUP BY DatePart('ww',Time_In);

但这给了我Syntax error (missing operator) in query expression 'Count(distinct jog_id)'.

我想念什么?

推荐答案

如果不使用子查询，则无法在Access中执行此操作.
例如:

You can't do this in Access without using a sub-query.
EX:

SELECT Count(*)
FROM
(SELECT DISTINCT Name FROM table1);

Here is a detailed article on the topic:

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