SQL服务器通过基于条件的排名和分组查询

Question

我正在尝试创建一个SQL查询，该查询将根据创建的日期对记录进行排名，然后在记录交互（请求和响应）的表中按eventId进行分组

日期计算将从当时创建的响应日期派生 - 请求日期已创建，但可能有多个响应和请求实例

1. 请求
2. 响应 - 响应（2）和请求（1）之间的DateDiff
3. 要求提供更多详情
4. 响应 - 响应（4）和请求（3）之间的DateDiff

我设法做了第一部分，即识别和排列事件，但无法确定如何分组;请参阅下面的查询和结果集：

WITH rows
AS (
    SELECT ID,
        IncidentId,
        Cust,
        Channel,
        TTypeID,
        DateCreated,
        RANK() OVER (PARTITION BY IncidentId ORDER BY Id) AS 'rownum',
        ROW_NUMBER() OVER (PARTITION BY IncidentId ORDER BY DateCreated) AS Counts
    FROM [dbo].[Thread]
    WHERE TypeId IN (3, 4, 2, 1)
    )
SELECT *
FROM (
    SELECT DISTINCT a.ID,
        a.incidentId,
        a.Channel,
        a.rownum,
        a.TypeID,
        a.datecreated
    FROM rows a
    JOIN rows b
        ON a.incidentId = b.incidentId
    WHERE a.TypeId IN (3, 4, 2)
    ) AS base



 ID Incident           Channel          Rownum  Type    DateCreated
 24108571   9436560     Form            1       3           2015-04-22 13:41:29.000
 24109189   9436560     E-mail          2       2           2015-04-22 13:48:21.000
 24109788   9436560     Form            3       3           2015-04-22 13:49:39.000
 24109789   9436560     Email           4       2           2015-04-22 13:50:37.000

我希望能够再次对结果进行排名，以便确定请求响应的数量。

输出应如下：

   ID       Incident           Channel      Rownum      Type                DateCreated             WaitTimeGrouping
 24108571   9436560         Form            1       3           2015-04-22 13:41:29.000             0
 24109189   9436560         E-mail          2       2           2015-04-22 13:48:21.000             1
 24109788   9436560         Form            3       3           2015-04-22 13:49:39.000                0
 24109789   9436560         Email           4       2           2015-04-22 13:50:37.000             2

Answer 1

让您入门的示例选项可能如下所示：

SELECT
    req.Incident,
    MAX( resp.DateCreated - req.DateCreated ),
    MIN( resp.DateCreated - req.DateCreated ),
    AVG( resp.DateCreated - req.DateCreated )
FROM Thread req
INNER JOIN Thread resp
    ON req.Incident = resp.Incident
    AND resp.Rownum = req.RowNum+1
WHERE req.Type = 3 -- "Request"?
AND resp.Type = 2 -- "Response"?
GROUP BY req.Incident

请注意，我们只是假设响应的Rownum始终是请求的Rownum + 1。如果无法保证，则需要另一个（子）查询来查找请求和响应记录之间的匹配。