按名称分组的连续日期范围内的最小和最大日期

Question

我有一个人的开始和结束日期的数据范围，我只想获取每个人的连续日期范围：

输入：

NAME | STARTDATE      | END DATE
--------------------------------------
MIKE | **2019-05-15** | 2019-05-16 
MIKE | 2019-05-17     | **2019-05-18**
MIKE | 2020-05-18     | 2020-05-19

预期的输出，如：

MIKE | **2019-05-15** | **2019-05-18** 
MIKE | 2020-05-18     | 2020-05-19

因此，对于该人，每个连续周期的输出基本上是MIN和MAX。

感谢任何帮助。

我已经尝试过以下查询：

With N AS (   SELECT Name, StartDate, EndDate
       , LastStop = MAX(EndDate) 
                    OVER (PARTITION BY Name ORDER BY StartDate, EndDate 
                          ROWS BETWEEN UNBOUNDED PRECEDING AND 1 PRECEDING)   FROM   Table  ), B AS (   SELECT Name, StartDate, EndDate
       , Block = SUM(CASE WHEN LastStop Is Null Then 1
                          WHEN LastStop < StartDate Then 1
                          ELSE 0
                    END)
                 OVER (PARTITION BY Name ORDER BY StartDate, LastStop)   FROM   N ) SELECT Name
     , MIN(StartDate) DateFrom
     , MAX(EndDate) DateTo FROM   B GROUP BY Name, Block ORDER BY Name, Block

但不考虑连续时间。显示相同的输入。

Answer 1

这里是使用临时统计表的示例

示例或dbFiddle

;with cte as (
Select A.[Name]
      ,B.D
      ,Grp  = datediff(day,'1900-01-01',D) - dense_rank() over (partition by [Name] Order by D)
 From  YourTable A
 Cross Apply ( 
                Select Top (DateDiff(DAY,StartDate,EndDate)+1) D=DateAdd(DAY,-1+Row_Number() Over (Order By (Select Null)),StartDate) 
                 From  master..spt_values n1,master..spt_values n2 
             ) B

)
Select [Name]
      ,StartDate= min(D)
      ,EndDate  = max(D)
 From  cte
 Group By [Name],Grp

返回

Name    StartDate   EndDate
MIKE    2019-05-15  2019-05-18
MIKE    2020-05-18  2020-05-19

为了帮助可视化，CTE会生成以下内容