Question

我需要根据每月文件中的日期创建一个日期范围，其结果按EmpID和StatusCode分组。

“开始”日期将是最早月份的开始日期，“结束”日期将是分组中最后一个月的最后一天。谢谢！

表：

EmpID   StatusCode  AsOF
12345   J   6/30/2014
12345   J   7/31/2014
12345   J   8/29/2014
12345   J   9/30/2014
12345   G   10/31/2014
12345   G   11/28/2014
12345   G   12/31/2014
12345   G   1/30/2015
12345   G   2/27/2015
12345   M   3/30/2015
12345   M   4/30/2015
12345   M   5/29/2015
12345   M   6/30/2015
12345   G   7/31/2015
12345   G   8/31/2015
12345   G   9/30/2015
12345   G   10/30/2015
12345   G   11/30/2015

预期结果：

EmpID   StatusCode  Start   End
12345   J   6/1/2014    9/30/2014
12345   G   10/1/2014   2/28/2015
12345   M   3/1/2015    6/30/2015
12345   G   7/1/2015    11/30/2015

Answer 1

group by逻辑不仅取决于EmpID和StatusCode（如问题中所述），还取决于所谓的gaps-and-islands。例如，预期输出有EmpID 12345和StatusCode G的2条记录，因为有2个岛屿（2014/10 - 2015/2和2015/7 - 2015/11），它们之间存在差距（2015/3 - 2015/6）。

示例数据：

我使用了@RazvanSocol非常好的样本数据来打字，但是这里包含它以防万一他的答案稍后修改。

CREATE TABLE #sample_Data (
    EmpID int NOT NULL,
    StatusCode CHAR(1) NOT NULL,
    AsOf DATE NOT NULL,
    UNIQUE (EmpID, AsOf)
)

INSERT INTO #sample_Data (EmpID, StatusCode, AsOf) VALUES 
(12345,'J','20140630'),
(12345,'J','20140731'),
(12345,'J','20140829'),
(12345,'J','20140930'),
(12345,'G','20141031'),
(12345,'G','20141128'),
(12345,'G','20141231'),
(12345,'G','20150130'),
(12345,'G','20150227'),
(12345,'M','20150330'),
(12345,'M','20150430'),
(12345,'M','20150529'),
(12345,'M','20150630'),
(12345,'G','20150731'),
(12345,'G','20150831'),
(12345,'G','20150930'),
(12345,'G','20151030'),
(12345,'G','20151130')

<强>答案：

假设您使用的是SQL Server 2012或更高版本，此答案将起作用。下面的查询利用Window Functions等lag和sum来确定群岛的开始位置并为其分配IslandNbr。在最终的外部查询中，有一个datediff计算用于确定该月的第一天，还有一个eomonth函数用于确定其相应输入AsOf日期的月份的最后一天

select b.EmpID
, b.StatusCode
, cast(dateadd(month, datediff(month, 0, min(b.AsOf)), 0)as date) as [Start]
, eomonth(max(b.AsOf)) as [End]
from (
    select a.EmpID
    , a.StatusCode
    , a.AsOf
    , sum(a.IslandBegin) over (partition by a.EmpID, a.StatusCode order by a.AsOf) as IslandNbr
    from (
        select d.EmpID
        , d.StatusCode
        , d.AsOf
        , case when datediff(month, lag(d.AsOf, 1, null) over (partition by d.EmpID, d.StatusCode order by d.AsOf asc), d.AsOf) = 1 then 0 else 1 end as IslandBegin
        from #sample_Data as d
        ) as a
    ) as b
group by b.EmpID
, b.StatusCode
, b.IslandNbr
order by 3

<强>输出：

输出完全符合预期结果。

+-------+------------+------------+------------+
| EmpID | StatusCode |   Start    |    End     |
+-------+------------+------------+------------+
| 12345 | J          | 2014-06-01 | 2014-09-30 |
| 12345 | G          | 2014-10-01 | 2015-02-28 |
| 12345 | M          | 2015-03-01 | 2015-06-30 |
| 12345 | G          | 2015-07-01 | 2015-11-30 |
+-------+------------+------------+------------+

Answer 2

您可以使用以下内容：

/*
CREATE TABLE Table1 (
    EmpID int NOT NULL,
    StatusCode CHAR(1) NOT NULL,
    AsOf DATE NOT NULL,
    UNIQUE (EmpID, AsOf)
)

INSERT INTO dbo.Table1 (EmpID, StatusCode, AsOf) VALUES 
(12345,'J','20140630'),
(12345,'J','20140731'),
(12345,'J','20140829'),
(12345,'J','20140930'),
(12345,'G','20141031'),
(12345,'G','20141128'),
(12345,'G','20141231'),
(12345,'G','20150130'),
(12345,'G','20150227'),
(12345,'M','20150330'),
(12345,'M','20150430'),
(12345,'M','20150529'),
(12345,'M','20150630'),
(12345,'G','20150731'),
(12345,'G','20150831'),
(12345,'G','20150930'),
(12345,'G','20151030'),
(12345,'G','20151130')
*/

SELECT DISTINCT Q2.EmpID, Q2.StatusCode, 
    DATEADD(MONTH,DATEDIFF(MONTH,'20000101',Q2.FirstAsOf),'20000101') AS StartDate,
    DATEADD(DAY,-1,DATEADD(MONTH,DATEDIFF(MONTH,'20000101',Q2.LastAsOf)+1,'20000101')) AS EndDate
FROM (
    SELECT *, 
        MIN(Q1.AsOf) OVER (PARTITION BY Q1.EmpID,Q1.StatusCode,Q1.Dif) AS FirstAsOf,
        MAX(Q1.AsOf) OVER (PARTITION BY Q1.EmpID,Q1.StatusCode,Q1.Dif) AS LastAsOf
    FROM (
        SELECT *, ROW_NUMBER() OVER (PARTITION BY t.EmpID ORDER BY t.AsOf)
            -ROW_NUMBER() OVER (PARTITION BY t.EmpID,t.StatusCode ORDER BY t.AsOf) AS Dif
        FROM dbo.Table1 t
    ) Q1
) Q2
ORDER BY EmpID, StartDate

单日期的日期范围

2 个答案: