如何计算没有。 sql 服务器中特定时间段一年中的天数

Question

以下是组织成员的医疗保险详细信息示例。我们必须找出不。每个成员在特定年份投保的天数。 以下数据的日期格式为 mm-dd-yyyy

SELECT \* FROM MED_INSURANCE

INSERT INTO MED_INSURANCE VALUES

('M1','1-1-2017','11-20-2017')
,('M1','12-31-2017','02-01-2018')
,('M1','02-15-2018','04-30-2018')
,('M1','06-10-2018','12-31-2018')
,('M2','1-1-2017 ','11-20-2017')
,('M2','12-31-2017','02-01-2018')
,('M3','02-15-2018','04-30-2018')
,('M3','06-10-2018','12-31-2018')
,('M4','1-1-2017','11-20-2017')
,('M4','12-31-2017','02-01-2018')
,('M5','02-15-2018','04-30-2018')
,('M5','06-10-2018','12-31-2018')
,('M6','01-01-2017','12-31-2019')
,('M7','12-31-2017','12-30-2018')
,('M8','1-1-2020','12-31-2020')
,('M9','06-30-2018','01-31-2020')

输出应该类似于

memberid        no_of_days_insured_in_2018
m1                      309
.
.
.
.
m7                      363

Answer 1

如果这是特定年份，正如您所暗示的，那么您可以 DATEDIFF 使用一些 CASE 表达式：

SELECT YD.ID,
       SUM(DATEDIFF(DAY,
                    CASE WHEN YD.StartDate < '20180101' THEN '20180101'
                         WHEN YD.StartDate >= '20190101' THEN NULL
                         ELSE YD.StartDate
                    END,
                    CASE WHEN YD.EndDate < '20180101' THEN NULL
                         WHEN YD.EndDate >= '20190101' THEN '20181231'
                         ELSE YD.EndDate
                    END) + 1) AS DaysIn2018
FROM (VALUES ('M1', '1-1-2017', '11-20-2017'),
             ('M1', '12-31-2017', '02-01-2018'),
             ('M1', '02-15-2018', '04-30-2018'),
             ('M1', '06-10-2018', '12-31-2018'),
             ('M2', '1-1-2017 ', '11-20-2017'),
             ('M2', '12-31-2017', '02-01-2018'),
             ('M3', '02-15-2018', '04-30-2018'),
             ('M3', '06-10-2018', '12-31-2018'),
             ('M4', '1-1-2017', '11-20-2017'),
             ('M4', '12-31-2017', '02-01-2018'),
             ('M5', '02-15-2018', '04-30-2018'),
             ('M5', '06-10-2018', '12-31-2018'),
             ('M6', '01-01-2017', '12-31-2019'),
             ('M7', '12-31-2017', '12-30-2018'),
             ('M8', '1-1-2020', '12-31-2020'),
             ('M9', '06-30-2018', '01-31-2020')) V (ID, StartDate, EndDate)
     CROSS APPLY(VALUES(V.ID, CONVERT(date,StartDate,101), CONVERT(date,V.EndDate,101)))YD(ID, StartDate, EndDate)
GROUP BY YD.ID;

如何计算没有。 sql 服务器中特定时间段一年中的天数

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sql-server

datediff