给定两个日期范围,确定两个日期是否重叠的最简单或最有效的方法是什么?

例如,假设我们有由DateTime变量StartDate1到EndDate1和StartDate2到EndDate2表示的范围。


当前回答

下面的查询给出了提供的日期范围(开始和结束日期)与table_name中的任何日期(开始和终止日期)重叠的ID

select id from table_name where (START_DT_TM >= 'END_DATE_TIME'  OR   
(END_DT_TM BETWEEN 'START_DATE_TIME' AND 'END_DATE_TIME'))

其他回答

简单的解决方案:

compare the two dates: 
    A = the one with smaller start date, B = the one with bigger start date
if(A.end < B.start)
    return false
return true

如果重叠本身也需要计算,可以使用以下公式:

overlap = max(0, min(EndDate1, EndDate2) - max(StartDate1, StartDate2))
if (overlap > 0) { 
    ...
}

由于对于不同的语言和环境有多种答案,这里有一个标准ANSISQL的答案。

在标准SQL中,它非常简单

(StartDate1, EndDate1) overlaps (StartDate2, EndDate2)

假设所有四列都是DATE或TIMESTAMP列。如果两个范围至少有一天相同(假设DATE值),则返回true

(但并非所有DBMS产品都支持此功能)


在PostgreSQL中,使用日期范围也很容易测试是否包含

daterange(StartDate1, EndDate1) @> daterange(StartDate2, EndDate2)

如果第二个范围完全包含在第一个范围中(与“重叠”不同),则上述值返回真

使用momentjs的简短回答:

function isOverlapping(startDate1, endDate1, startDate2, endDate2){ 
    return moment(startDate1).isSameOrBefore(endDate2) && 
    moment(startDate2).isSameOrBefore(endDate1);
}

答案基于上述答案,但缩短了。

在Microsoft SQL SERVER中-SQL函数

CREATE FUNCTION IsOverlapDates 
(
    @startDate1 as datetime,
    @endDate1 as datetime,
    @startDate2 as datetime,
    @endDate2 as datetime
)
RETURNS int
AS
BEGIN
DECLARE @Overlap as int
SET @Overlap = (SELECT CASE WHEN  (
        (@startDate1 BETWEEN @startDate2 AND @endDate2) -- caters for inner and end date outer
        OR
        (@endDate1 BETWEEN @startDate2 AND @endDate2) -- caters for inner and start date outer
        OR
        (@startDate2 BETWEEN @startDate1 AND @endDate1) -- only one needed for outer range where dates are inside.
        ) THEN 1 ELSE 0 END
    )
    RETURN @Overlap

END
GO

--Execution of the above code
DECLARE @startDate1 as datetime
DECLARE @endDate1 as datetime
DECLARE @startDate2 as datetime
DECLARE @endDate2 as datetime
DECLARE @Overlap as int
SET @startDate1 = '2014-06-01 01:00:00' 
SET @endDate1 =   '2014-06-01 02:00:00'
SET @startDate2 = '2014-06-01 01:00:00' 
SET @endDate2 =   '2014-06-01 01:30:00'

SET @Overlap = [dbo].[IsOverlapDates]  (@startDate1, @endDate1, @startDate2, @endDate2)

SELECT Overlap = @Overlap