获取开始日期和结束日期之间的日期间隔记录

Question

>我有两个日期开始日期和结束日期。我怎么知道在这两个日期之间，我得到了 01/01 意味着新年。

例如：

Table test 
id  start date    End date 
1   02/03/2013   19/09/2016
2   15/02/2015   30/06/2015

输出

id  start date    End date  
1   02/03/2013   31/12/2013
1   01/01/2014   31/12/2014
1   01/01/2015   31/12/2015
1   01/01/2016   19/09/2016
2   15/02/2015   30/06/2015

怎么做这样的事情？

Answer 1

你会知道年份部分是否不同：

select t.*,
       (case when year(startdate) < year(enddate) then 1
             else 0
        end) as HasNewYear
from table t;

Answer 2

您可以使用递归 CTE 查找两个日期之间的所有年份，然后将日期投射到DATETIME对象以获得所需的输出：

;WITH CTE AS (
SELECT ID, DATEPART(YEAR, STARTDATE) AS YR, ENDDATE
FROM TABLE1
UNION ALL
SELECT ID, YR+1, ENDDATE
FROM CTE
WHERE YR < DATEPART(YEAR,ENDDATE))
SELECT A.ID, CASE WHEN CAST(A.YR AS VARCHAR)+'-01-01' > B.STARTDATE THEN CAST(A.YR AS VARCHAR)+'-01-01' ELSE B.STARTDATE END AS STARTDATE, CASE WHEN CAST(A.YR AS VARCHAR)+'-12-31' < B.ENDDATE THEN CAST(A.YR AS VARCHAR)+'-12-31' ELSE B.ENDDATE END AS ENDDATE
FROM CTE AS A
JOIN TABLE1 AS B
ON A.ID=B.ID
ORDER BY A.ID