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！

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'))

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);
    }

对于ruby，我也发现了这一点：

class Interval < ActiveRecord::Base

  validates_presence_of :start_date, :end_date

  # Check if a given interval overlaps this interval    
  def overlaps?(other)
    (start_date - other.end_date) * (other.start_date - end_date) >= 0
  end

  # Return a scope for all interval overlapping the given interval, including the given interval itself
  named_scope :overlapping, lambda { |interval| {
    :conditions => ["id <> ? AND (DATEDIFF(start_date, ?) * DATEDIFF(?, end_date)) >= 0", interval.id, interval.end_date, interval.start_date]
  }}

end

在这里找到它，解释很好->http://makandracards.com/makandra/984-test-if-two-date-ranges-overlap-in-ruby-or-rails

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) { 
    ...
}

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