在SQL中查找重叠日期

每个注册都有一个start_date和end_date。 如何以任何方式找到与另一个重叠的注册。

谢谢！

Answer 1

重叠测试的正确答案是This.Start vs Other.End ，如此处所述http://c2.com/cgi/wiki?TestIfDateRangesOverlap

 WHERE A.start < B.end AND B.start < A.end 

如果您认为“触摸”日期为重叠，请将<更改为<=

 Jan1 - Jan13 Jan13 - Jan15 

返回重叠<=但不重叠<

Answer 2

这只是一个SQL问题……我认为这个SQL会为你做的：

 select r1.* from registrations r1, registrations r2 where r1.start_date < r2.start_date and r1.end_date > r2.start_date 

在Rails中你会这样做：

 registrations = Registration.find_by_sql(sql) 

其中sql等于上面的sql代码。

Answer 3

这会找到两个范围之间有任何重叠的任何范围1，即使一个范围没有完全包含在另一个范围内。

 select r1.* from registrations r1 JOIN registrations r2 ON r1.start_date between r2.start_date AND r2.end_date 

Answer 4

标准SQL有一个OVERLAPS运算符。

 CREATE TABLE over_laps ( start_date date NOT NULL, end_date date NOT NULL, CONSTRAINT over_laps_pkey PRIMARY KEY (start_date, end_date), CONSTRAINT over_laps_check CHECK (start_date < end_date) ) insert into over_laps values ('2011-01-10', '2011-01-15'), ('2011-01-08', '2011-01-09'), ('2011-01-09', '2011-01-10'), ('2011-01-09', '2011-01-11'), ('2011-01-10', '2011-01-12'), ('2011-01-11', '2011-01-13'), ('2011-01-13', '2011-01-15'), ('2011-01-14', '2011-01-16'), ('2011-01-15', '2011-01-17'), ('2011-01-17', '2011-01-19'); select t1.start_date start_1, t1.end_date end_1, t2.start_date start_2, t2.end_date end_2 from over_laps t1 inner join over_laps t2 on ((t1.start_date, t1.end_date) overlaps (t2.start_date, t2.end_date)) -- Exclude rows that overlap themselves, a trivial case in a self-joined table. where t1.start_date <> t2.start_date and t1.end_date <> t2.end_date