顯示日期範圍 - 差距和羣島

Question

我有表，看起來像這樣：

+------------+------+ 
| Date | Name | 
+------------+------+ 
| 2017-01-07 | A | 
| 2017-01-08 | A | 
| 2017-01-09 | A | 
| 2017-01-12 | A | 
| 2017-01-07 | B | 
| 2017-01-08 | B | 
| 2017-01-09 | B | 
+------------+------+ 

我希望能夠把它變成如下：

+-------------------------+------+ 
|  Date Range  | Name | 
+-------------------------+------+ 
| 2017-01-07 - 2017-01-09 | A | 
| 2017-01-07 - 2017-01-09 | B | 
| 2017-01-12    | A | 
+-------------------------+------+ 

代碼將僅查找連續日期的最小值和最大值，使用名稱列對結果進行分組，然後將最小和最大日期列爲一列中的「從和到」字符串。

我在嘗試僅列出連續日期時遇到問題。請注意，上面的第三個條目獲取它自己的條目，因爲它與先前條目中的「A」的日期範圍不連續。

編輯：請注意：這是特定於SQL Server 2008，它不允許使用LAG功能。

---

編輯2： 通過McNets提供的原來的答覆工作SQL Server 2012的精細我在這裏包含它，因爲它的更好，如果你有SQL Server 2012的開始。

;WITH CalcDiffDays AS 
(
    SELECT Date, Name, 
    CONCAT (Name, CAST(DATEDIFF(DAY, LAG(Date, 1, Date - 1) OVER (PARTITION BY Name ORDER BY Name, Date), Date) AS VARCHAR(10))) AS NumDays 
    FROM @tmpTable 
) 
SELECT CONCAT(CONVERT(VARCHAR(20), MIN(Date), 102), ' - ', CONVERT(VARCHAR(20), MAX(Date), 102)) AS [Data Range], Name 
FROM CalcDiffDays 
GROUP BY NumDays, Name; 

Answer 1

首先我給整個表添加了一個行號。

WITH RowN AS 
(
    SELECT Date, Name, ROW_NUMBER() OVER (ORDER BY Name, Date) RN 
    FROM #T 
) 

然後我加入了這個表格，只是爲了計算日期之間的日子。

,CalcDiffDays AS 
(
    SELECT RowN.Date, RowN.Name, 
     ISLAND = RowN.Name + 
     CASE 
      WHEN RowN.RN > 1 AND RowN.Name = R2.Name THEN CAST(DATEDIFF(day, R2.Date, RowN.Date) AS VARCHAR(20)) 
      ELSE '1' 
     END 
    FROM RowN 
     LEFT JOIN RowN R2 ON R2.RN = RowN.RN-1 
) 

GAPS。相同名稱的連續日期之間有多少天。

ISLANDS。通過將名稱添加到計算的天數。

+---------------------+------+---------+ 
|   Date  | Name | NumDays | 
+---------------------+------+---------+ 
| 07.01.2017 00:00:00 | A | A1 | 
+---------------------+------+---------+ 
| 08.01.2017 00:00:00 | A | A1 | 
+---------------------+------+---------+ 
| 09.01.2017 00:00:00 | A | A1 | 
+---------------------+------+---------+ 
| 12.01.2017 00:00:00 | A | A3 | 
+---------------------+------+---------+ 
| 07.01.2017 00:00:00 | B | B1 | 
+---------------------+------+---------+ 
| 08.01.2017 00:00:00 | B | B1 | 
+---------------------+------+---------+ 
| 09.01.2017 00:00:00 | B | B1 | 
+---------------------+------+---------+ 

第二部分：獲取每個島的MIN和MAX日期。

WITH RowN AS 
(
    SELECT Date, Name, ROW_NUMBER() OVER (ORDER BY Name, Date) RN 
    FROM #T 
) 
,CalcDiffDays AS 
(
    SELECT RowN.Date, RowN.Name, 
     ISLAND = RowN.Name + 
     CASE 
      WHEN RowN.RN > 1 AND RowN.Name = R2.Name THEN CAST(DATEDIFF(day, R2.Date, RowN.Date) AS VARCHAR(20)) 
      ELSE '1' 
     END 
    FROM RowN 
     LEFT JOIN RowN R2 ON R2.RN = RowN.RN-1 
)  
SELECT CONVERT(VARCHAR(20), MIN(Date), 102) + ' - ' + CONVERT(VARCHAR(20), MAX(Date), 102) AS [Data Range], Name 
FROM CalcDiffDays 
GROUP BY ISLAND, Name 
ORDER BY MIN(Date); 

+-------------------------+------+ 
|  Data Range  | Name | 
+-------------------------+------+ 
| 2017.01.07 - 2017.01.09 | A | 
+-------------------------+------+ 
| 2017.01.07 - 2017.01.09 | B | 
+-------------------------+------+ 
| 2017.01.12 - 2017.01.12 | A | 
+-------------------------+------+ 

可以點擊此處查看：http://rextester.com/MHLEEJ50479