sql 判断两个时间段是否有交集

本文转自CSDN 链接地址：http://blog.csdn.net/dasihg/article/details/8450195  

时间段：starttime_1到endtime_1，starttime_2到endtime_2

SQL语句：where least(endtime_1, endtime_2) > greatest(starttime_1, starttime_2)

解释：least取最小值，greatest取最大值。



创建函数least、greatest



CREATE FUNCTION least

(

 @time1 datetime,

 @time2 datetime

)

RETURNS datetime

AS

BEGIN

declare @ret datetime

 if(@time2>@time1)set @ret=@time1

 else set @ret=@time2

return @ret

END

GO



 



CREATE FUNCTION greatest

(

 @time1 datetime,

 @time2 datetime

)

RETURNS datetime

AS

BEGIN

declare @ret datetime

 if(@time2<@time1)set @ret=@time1

 else set @ret=@time2

return @ret

END

GO