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
为了涵盖PHP/LaravelCarbon包中的所有重叠情况,您可以在Charles的答案中展开逻辑,如下所示。
if ( ($startTime1->between($startTime2, $endTime2, true) || $endTime1->between($startTime2, $endTime2, true)) || (($startTime1 <= $endTime2) && ($endTime2 <= $endTime1)) ){
//Complete Overlap, Partial Left Overlap, Partial Right Overlap.
}
这将检查StartTime1是否在(StartTime2-EndTime2)范围之间,或者EndTime1是否位于(StartTime2-EndTime2的范围之间。
其余部分完全重叠,如其他答案所述。
其他回答
如果您使用的日期范围尚未结束(仍在进行中),例如未设置endDate='0000-00-00'您不能使用BETWEEN,因为0000-00-00不是有效日期!
我使用了这个解决方案:
(Startdate BETWEEN '".$startdate2."' AND '".$enddate2."') //overlap: starts between start2/end2
OR (Startdate < '".$startdate2."'
AND (enddate = '0000-00-00' OR enddate >= '".$startdate2."')
) //overlap: starts before start2 and enddate not set 0000-00-00 (still on going) or if enddate is set but higher then startdate2
如果startdate2高于enddate,则没有重叠!
这里有一个可以在本地使用的通用方法。
// Takes a list and returns all records that have overlapping time ranges.
public static IEnumerable<T> GetOverlappedTimes<T>(IEnumerable<T> list, Func<T, bool> filter, Func<T,DateTime> start, Func<T, DateTime> end)
{
// Selects all records that match filter() on left side and returns all records on right side that overlap.
var overlap = from t1 in list
where filter(t1)
from t2 in list
where !object.Equals(t1, t2) // Don't match the same record on right side.
let in1 = start(t1)
let out1 = end(t1)
let in2 = start(t2)
let out2 = end(t2)
where in1 <= out2 && out1 >= in2
let totover = GetMins(in1, out1, in2, out2)
select t2;
return overlap;
}
public static void TestOverlap()
{
var tl1 = new TempTimeEntry() { ID = 1, Name = "Bill", In = "1/1/08 1:00pm".ToDate(), Out = "1/1/08 4:00pm".ToDate() };
var tl2 = new TempTimeEntry() { ID = 2, Name = "John", In = "1/1/08 5:00pm".ToDate(), Out = "1/1/08 6:00pm".ToDate() };
var tl3 = new TempTimeEntry() { ID = 3, Name = "Lisa", In = "1/1/08 7:00pm".ToDate(), Out = "1/1/08 9:00pm".ToDate() };
var tl4 = new TempTimeEntry() { ID = 4, Name = "Joe", In = "1/1/08 3:00pm".ToDate(), Out = "1/1/08 8:00pm".ToDate() };
var tl5 = new TempTimeEntry() { ID = 1, Name = "Bill", In = "1/1/08 8:01pm".ToDate(), Out = "1/1/08 8:00pm".ToDate() };
var list = new List<TempTimeEntry>() { tl1, tl2, tl3, tl4, tl5 };
var overlap = GetOverlappedTimes(list, (TempTimeEntry t1)=>t1.ID==1, (TempTimeEntry tIn) => tIn.In, (TempTimeEntry tOut) => tOut.Out);
Console.WriteLine("\nRecords overlap:");
foreach (var tl in overlap)
Console.WriteLine("Name:{0} T1In:{1} T1Out:{2}", tl.Name, tl.In, tl.Out);
Console.WriteLine("Done");
/* Output:
Records overlap:
Name:Joe T1In:1/1/2008 3:00:00 PM T1Out:1/1/2008 8:00:00 PM
Name:Lisa T1In:1/1/2008 7:00:00 PM T1Out:1/1/2008 9:00:00 PM
Done
*/
}
我认为最简单的方法是比较EndDate1是否在StartDate2之前,EndDate2是否在StartDate 1之前。
当然,如果您正在考虑StartDate总是在EndDate之前的时间间隔。
这是我使用moment.js的javascript解决方案:
// Current row dates
var dateStart = moment("2014-08-01", "YYYY-MM-DD");
var dateEnd = moment("2014-08-30", "YYYY-MM-DD");
// Check with dates above
var rangeUsedStart = moment("2014-08-02", "YYYY-MM-DD");
var rangeUsedEnd = moment("2014-08-015", "YYYY-MM-DD");
// Range covers other ?
if((dateStart <= rangeUsedStart) && (rangeUsedEnd <= dateEnd)) {
return false;
}
// Range intersects with other start ?
if((dateStart <= rangeUsedStart) && (rangeUsedStart <= dateEnd)) {
return false;
}
// Range intersects with other end ?
if((dateStart <= rangeUsedEnd) && (rangeUsedEnd <= dateEnd)) {
return false;
}
// All good
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) {
...
}