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

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
         */
    }

其他回答

关于时间关系(或任何其他区间关系)的推理,请考虑Allen的区间代数。它描述了两个区间之间可能存在的13种关系。你可以找到其他参考资料——“艾伦间隔”似乎是一个有效的搜索词。您还可以在Snodgrass的《用SQL开发面向时间的应用程序》(PDF,网址为)、《日期、达文和洛伦兹时间数据与关系模型》(2002年)或《时间与关系理论:关系模型与SQL中的时间数据库》(2014年;实际上是TD&RM的第二版)中找到有关这些操作的信息。


简短的答案是:给定两个日期间隔A和B,其中包含.start和.end以及约束.start<=.end,则两个间隔重叠,如果:

A.end >= B.start AND A.start <= B.end

您可以调整>=vs>和<=vs<的使用,以满足重叠程度的要求。


ErikE评论:

如果你数点有趣的事情,你只能得到13。。。当我疯狂地计算时,我可以得到“两个区间可以有15种可能的关系”。通过合理的计算,我只能得到6种关系,如果你不在乎A还是B先出现,我只能获得3种关系(不相交,部分相交,一种完全在另一种内)。15是这样的:[之前:之前,开始,内部,结束,之后],[开始:开始,内部、结束,之后】,[内部:内部,结束、之后],[结束:结束,之后,],[之后:之后]。

我认为你不能计算“之前:之前”和“之后:之后”这两个条目。如果你将某些关系与它们的逆关系等同起来,我可以看到7个条目(参见参考维基百科URL中的图表;它有7个条目,其中6个条目具有不同的逆关系,而equals没有不同的逆)。三个是否合理取决于你的要求。

----------------------|-------A-------|----------------------
    |----B1----|
           |----B2----|
               |----B3----|
               |----------B4----------|
               |----------------B5----------------|
                      |----B6----|
----------------------|-------A-------|----------------------
                      |------B7-------|
                      |----------B8-----------|
                         |----B9----|
                         |----B10-----|
                         |--------B11--------|
                                      |----B12----|
                                         |----B13----|
----------------------|-------A-------|----------------------

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
         */
    }

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'))

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

我认为,在以下情况下,两个范围重叠就足够了:

(StartDate1 <= EndDate2) and (StartDate2 <= EndDate1)