我正在做一些基于员工工作时间的报告.在某些情况下,数据包含两个单独的记录,用于确切的单个时间块.
这是该表的基本版本和一些示例记录:
EmployeeID StartTime EndTime
数据:
EmpID Start End ---------------------------- #1001 10:00 AM 12:00 PM #1001 4:00 PM 5:30 PM #1001 5:30 PM 8:00 PM
在该示例中,最后两个记录在时间上是连续的.我想写一个组合任何相邻记录的查询,所以结果集是这样的:
EmpID Start End ---------------------------- #1001 10:00 AM 12:00 PM #1001 4:00 PM 8:00 PM
理想情况下,它还应该能够处理2个以上的相邻记录,但这不是必需的.
解决方法
本文为您的问题提供了一些可能的解决方案
这个似乎是最直接的:
WITH StartTimes AS ( SELECT DISTINCT username,starttime FROM dbo.Sessions AS S1 WHERE NOT EXISTS (SELECT * FROM dbo.Sessions AS S2 WHERE S2.username = S1.username AND S2.starttime < S1.starttime AND S2.endtime >= S1.starttime) ),EndTimes AS ( SELECT DISTINCT username,endtime FROM dbo.Sessions AS S1 WHERE NOT EXISTS (SELECT * FROM dbo.Sessions AS S2 WHERE S2.username = S1.username AND S2.endtime > S1.endtime AND S2.starttime <= S1.endtime) ) SELECT username,starttime,(SELECT MIN(endtime) FROM EndTimes AS E WHERE E.username = S.username AND endtime >= starttime) AS endtime FROM StartTimes AS S;