当增量值重新开始时如何排除行? [英] How do I exclude rows when an incremental value starts over?

问题描述

我是一个新手海报，但在这里花了很多时间研究答案.我不太清楚如何使用 SQL Server 2008 R2 创建 SQL 结果集，该结果集可能应该使用更现代版本的领先/滞后.我试图根据一列的排序来聚合数据，但每个序列中可能有不同数量的实例.我知道序列结束的唯一方法是下一行的序列号较低.所以它可能是 1-2、1-2-3-4、1-2-3，我必须弄清楚如何从中制作 3 个聚合.

I am a newbie poster but have spent a lot of time researching answers here. I can't quite figure out how to create a SQL result set using SQL Server 2008 R2 that should probably be using lead/lag from more modern versions. I am trying to aggregate data based on sequencing of one column, but there can be varying numbers of instances in each sequence. The only way I know a sequence has ended is when the next row has a lower sequence number. So it may go 1-2, 1-2-3-4, 1-2-3, and I have to figure out how to make 3 aggregates out of that.

源数据是连接表，看起来像这样(请帮我格式化):

Source data is joined tables that look like this (please help me format):

recordID instanceDate moduleID iResult interactionNum
1356    10/6/15 16:14   1        68          1
1357    10/7/15 16:22   1        100         2
1434    10/9/15 16:58   1        52          1
1435    10/11/15 17:00  1        60          2
1436    10/15/15 16:57  1        100         3
1437    10/15/15 16:59  1        100         4

我需要找到一种方法，根据最后一列中的值，将本示例中的前 2 行与后 4 行分开.

I need to find a way to separate the first 2 rows from the last 4 rows in this example, based on values in the last column.

我希望最终得到的是一个看起来像这样的结果集，它根据分组平均 iResult 列并从分组中获取第一个 instanceDate:

What I would love to ultimately get is a result set that looks like this, which averages the iResult column based on the grouping and takes the first instanceDate from the grouping:

instanceDate    moduleID    iResult
10/6/15           1          84
10/9/15           1          78

如果我能找到一种方法来分隔组，我可以使用 MIN 和 AVG 进行聚合以获得此结果.数据按 instanceDate 排序(请忽略此处的日期格式)，然后当查询找到一个交互数小于前一行的行时，应该发生交互数和组分离(通常以 '1' 重新开始，但不是总是，所以更喜欢只用较低或相等的整数值分隔).

I can aggregate to get this result using MIN and AVG if I can just find a way to separate the groups. The data is ordered by instanceDate (please ignore the date formatting here) then interactionNum and the group separation should happen when the query finds a row where the interactionNum is <= than the previous row (will usually start over with '1' but not always, so prefer just to separate on a lower or equal integer value).

这是我到目前为止的查询(包括提供上述数据集的连接):

Here is the query I have so far (includes the joins that give the above data set):

SELECT 
    X.* 
FROM
   (SELECT TOP 100 PERCENT   
        instanceDate, b.ModuleID, iResult, b.interactionNum 
    FROM 
        (firstTable a  
    INNER JOIN 
        secondTable b ON b.someID = a.someID)       
    WHERE 
        a.someID = 2        
        AND b.otherID LIKE 'xyz'    
        AND a.ModuleID = 1
    ORDER BY 
        instanceDate) AS  X

OUTER APPLY

(SELECT TOP 1 
     *
 FROM
     (SELECT    
          instanceDate, d.ModuleID, iResult, d.interactionNum   
      FROM 
          (firstTable c  
      INNER JOIN 
          secondTable d ON d.someID = c.someID) 
      WHERE 
          c.someID = 2      
          AND d.otherID LIKE 'xyz'  
          AND c.ModuleID = 1    
          AND d.interactionNum = X.interactionNum
          AND c.instanceDate < X.instanceDate)  X2
      ORDER BY 
          instanceDate DESC) Y
WHERE 
    NOT EXISTS (SELECT Y.interactionNum INTERSECT SELECT X.interactionNum)

但这会返回一个像这样的临时结果集:

But this is returning an interim result set like this:

instanceDate    ModuleID    iResult interactionNum
10/6/15 16:10   1            68         1
10/6/15 16:14   1            100        2
10/15/15 16:57  1            100        3
10/15/15 16:59  1            100        4

问题是interactionNum 3, 4 不属于这个结果集.当我遍历此查询时，它们将进入下一个结果集.如何将它们排除在此迭代中的结果集之外?我需要这个查询的结果集只包含前两行，看到"源数据的第 3 行的 interactionNum 值低于第 2 行.

and the problem is that interactionNum 3, 4 do not belong in this result set. They would go in the next result set when I loop over this query. How do I keep them out of the result set in this iteration? I need the result set from this query to just include the first two rows, 'seeing' that row 3 of the source data has a lower value for interactionNum than row 2 has.

推荐答案

不确定应该使用什么 ModuleID，但我猜你正在寻找这样的东西:

Not sure what ModuleID was supposed to be used, but I guess you're looking for something like this:

select min (instanceDate), [moduleID], avg([iResult])
from (
  select *,row_number() over (partition by [moduleID] order by instanceDate) as RN
  from Table1
) X
group by [moduleID], RN - [interactionNum]

这里的想法是为每个moduleid创建一个带有row_number的运行编号，然后使用它与InteractionNum之间的差异作为分组标准.

The idea here is to create a running number with row_number for each moduleid, and then use the difference between that and InteractionNum as grouping criteria.

SQL Fiddle

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