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。
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
我会的
StartDate1.IsBetween(StartDate2, EndDate2) || EndDate1.IsBetween(StartDate2, EndDate2)
IsBetween是这样的
public static bool IsBetween(this DateTime value, DateTime left, DateTime right) {
return (value > left && value < right) || (value < left && value > right);
}
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
此处发布的解决方案不适用于所有重叠范围。。。
----------------------|-------A-------|---------------------- |----B1----| |----B2----| |----B3----| |----------B4----------| |----------------B5----------------| |----B6----| ----------------------|-------A-------|---------------------- |------B7-------| |----------B8-----------| |----B9----| |----B10-----| |--------B11--------| |----B12----| |----B13----| ----------------------|-------A-------|----------------------
我的工作解决方案是:
AND ( ('start_date' BETWEEN STARTDATE AND ENDDATE) -- caters for inner and end date outer OR ('end_date' BETWEEN STARTDATE AND ENDDATE) -- caters for inner and start date outer OR (STARTDATE BETWEEN 'start_date' AND 'end_date') -- only one needed for outer range where dates are inside. )
这是我的解决方案,当值不重叠时返回真值:
X开始1Y端1
开始2B端2
TEST1: (X <= A || X >= B)
&&
TEST2: (Y >= B || Y <= A)
&&
TEST3: (X >= B || Y <= A)
X-------------Y
A-----B
TEST1: TRUE
TEST2: TRUE
TEST3: FALSE
RESULT: FALSE
---------------------------------------
X---Y
A---B
TEST1: TRUE
TEST2: TRUE
TEST3: TRUE
RESULT: TRUE
---------------------------------------
X---Y
A---B
TEST1: TRUE
TEST2: TRUE
TEST3: TRUE
RESULT: TRUE
---------------------------------------
X----Y
A---------------B
TEST1: FALSE
TEST2: FALSE
TEST3: FALSE
RESULT: FALSE
这里还有一个使用JavaScript的解决方案。我的解决方案的特点:
将空值处理为无穷大假设下限是包含的,上限是不包含的。附带一系列测试
这些测试基于整数,但由于JavaScript中的日期对象是可比较的,因此您也可以添加两个日期对象。或者您可以输入毫秒时间戳。
代码:
/**
* Compares to comparable objects to find out whether they overlap.
* It is assumed that the interval is in the format [from,to) (read: from is inclusive, to is exclusive).
* A null value is interpreted as infinity
*/
function intervalsOverlap(from1, to1, from2, to2) {
return (to2 === null || from1 < to2) && (to1 === null || to1 > from2);
}
测验:
describe('', function() {
function generateTest(firstRange, secondRange, expected) {
it(JSON.stringify(firstRange) + ' and ' + JSON.stringify(secondRange), function() {
expect(intervalsOverlap(firstRange[0], firstRange[1], secondRange[0], secondRange[1])).toBe(expected);
});
}
describe('no overlap (touching ends)', function() {
generateTest([10,20], [20,30], false);
generateTest([20,30], [10,20], false);
generateTest([10,20], [20,null], false);
generateTest([20,null], [10,20], false);
generateTest([null,20], [20,30], false);
generateTest([20,30], [null,20], false);
});
describe('do overlap (one end overlaps)', function() {
generateTest([10,20], [19,30], true);
generateTest([19,30], [10,20], true);
generateTest([10,20], [null,30], true);
generateTest([10,20], [19,null], true);
generateTest([null,30], [10,20], true);
generateTest([19,null], [10,20], true);
});
describe('do overlap (one range included in other range)', function() {
generateTest([10,40], [20,30], true);
generateTest([20,30], [10,40], true);
generateTest([10,40], [null,null], true);
generateTest([null,null], [10,40], true);
});
describe('do overlap (both ranges equal)', function() {
generateTest([10,20], [10,20], true);
generateTest([null,20], [null,20], true);
generateTest([10,null], [10,null], true);
generateTest([null,null], [null,null], true);
});
});
使用karma&jasmine&PhantomJS运行时的结果:
PhantomJS 1.9.8(Linux):执行20次成功(0.003秒/0.004秒)
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