使用SQL显示组中的最小计数和最大计数 [英] Use SQL to display count of min and count of max within group

问题描述

我正在寻找一种方法来计算等于组的最小值或最大值的项目数.我每隔几天收到一次商品，每两周输入一次.我需要查看每个EntryDate的最小值和最大值ReceivedDate，以及最小值和最大值处的项目计数.在MS Access中使用SQL.

I am looking for a way to count the number of items that are equal to the min or max of a group. I have items that are received every few days and are entered bi-weekly. I need to see the Min and Max ReceivedDate for each EntryDate, and the Count of items at the Min and at the Max. Using SQL in MS Access.

tblItem

|    EntryDate    |   ReceivedDate   |
--------------------------------------
|   01/01/2016    |    16/12/2015    |
|   01/01/2016    |    15/12/2015    |
|   01/01/2016    |    10/12/2015    |
|   01/01/2016    |    10/12/2015    |
|   01/01/2016    |    10/12/2015    |
|   01/01/2016    |    10/12/2015    |
|   15/01/2016    |    05/01/2016    |
|   15/01/2016    |    05/01/2016    |
|   15/01/2016    |    04/01/2016    |
|   15/01/2016    |    03/01/2016    |
|   15/01/2016    |    03/01/2016    |
|   15/01/2016    |    03/01/2016    |

当前查询

SELECT tblItem.EntryDate, 
Min(tblItem.ReceivedDate) AS MinReceivedDate, 
Max(tblItem.ReceivedDate) AS MaxReceivedDate
FROM tblItem
GROUP BY tblItem.EntryDate;

电流输出

Query1

| EntryDate  | MinReceivedDate | MaxReceivedDate |
--------------------------------------------------
| 01/01/2016 |    10/12/2015   |   16/12/2015    |
| 15/01/2016 |    03/01/2016   |   05/01/2016    |

所需的输出

Query1

| EntryDate  | MinReceivedDate | CountOfMin | MaxReceivedDate | CountOfMax |
---------------------------------------------------------------------------
| 01/01/2016 |    10/12/2015   |      4     |   16/12/2015    |      1     |
| 15/01/2016 |    03/01/2016   |      3     |   05/01/2016    |      2     |

推荐答案

我不知道MS Access是否允许这样的子查询.如果这不起作用，请让我知道，我将删除答案.否则，则:

I don't know if MS Access allows subqueries like this. If this doesn't work, please let me know and I'll delete the answer. Otherwise though:

SELECT
    SQ.EntryDate,
    SQ.MinReceivedDate,
    SUM(IIF(I.ReceivedDate = SQ.MinReceivedDate, 1, 0)) AS CountOfMin,
    SQ.MaxReceivedDate,
    SUM(IIF(I.ReceivedDate = SQ.MaxReceivedDate, 1, 0)) AS CountOfMax
FROM (
    SELECT
        SQI.EntryDate,
        MIN(SQI.ReceivedDate) AS MinReceivedDate,
        MAX(SQI.ReceivedDate) AS MaxReceivedDate
    FROM
        tblItem SQI
    GROUP BY
        SQI.EntryDate
    ) SQ
INNER JOIN tblItem I ON I.EntryDate = SQ.EntryDate
GROUP BY
    SQ.EntryDate,
    SQ.MinReceivedDate,
    SQ.MaxReceivedDate

这篇关于使用SQL显示组中的最小计数和最大计数的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！