检查 MySQL 中日期范围的重叠

此表用于存储会话(事件) :

CREATE TABLE session (
id int(11) NOT NULL AUTO_INCREMENT
, start_date date
, end_date date
);


INSERT INTO session
(start_date, end_date)
VALUES
("2010-01-01", "2010-01-10")
, ("2010-01-20", "2010-01-30")
, ("2010-02-01", "2010-02-15")
;

我们不希望范围之间发生冲突。
假设我们需要插入一个从 2010-01-05到 2010-01-25的新会话。
我们想知道冲突的会议。

以下是我的疑问:

SELECT *
FROM session
WHERE "2010-01-05" BETWEEN start_date AND end_date
OR "2010-01-25" BETWEEN start_date AND end_date
OR "2010-01-05" >= start_date AND "2010-01-25" <= end_date
;

结果如下:

+----+------------+------------+
| id | start_date | end_date   |
+----+------------+------------+
|  1 | 2010-01-01 | 2010-01-10 |
|  2 | 2010-01-20 | 2010-01-30 |
+----+------------+------------+

还有更好的方法吗？

小提琴

53894 次浏览
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最佳答案

I had such a query with a calendar application I once wrote. I think I used something like this:

... WHERE new_start < existing_end
AND new_end   > existing_start;

UPDATE This should definitely work ((ns, ne, es, ee) = (new_start, new_end, existing_start, existing_end)):

  1. ns - ne - es - ee: doesn't overlap and doesn't match (because ne < es)
  2. ns - es - ne - ee: overlaps and matches
  3. es - ns - ee - ne: overlaps and matches
  4. es - ee - ns - ne: doesn't overlap and doesn't match (because ns > ee)
  5. es - ns - ne - ee: overlaps and matches
  6. ns - es - ee - ne: overlaps and matches

Here is a fiddle

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SELECT * FROM tbl WHERE
existing_start BETWEEN $newStart AND $newEnd OR
existing_end BETWEEN $newStart AND $newEnd OR
$newStart BETWEEN existing_start AND existing_end


if (!empty($result))
throw new Exception('We have overlapping')

These 3 lines of sql clauses cover the 4 cases of overlapping required.

小开

Lamy's answer is good, but you can optimize it a little more.

SELECT * FROM tbl WHERE
existing_start BETWEEN $newSTart AND $newEnd OR
$newStart BETWEEN existing_start AND existing_end

This will catch all four scenarios where the ranges overlap and exclude the two where they don't.

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I had faced the similar problem. My problem was to stop booking between a range of blocked dates. For example booking is blocked for a property between 2nd may to 7th may. I needed to find any kind of overlapping date to detect and stop the booking. My solution is similar to LordJavac. 

SELECT * FROM ib_master_blocked_dates WHERE venue_id=$venue_id AND
(
(mbd_from_date BETWEEN '$from_date' AND '$to_date')
OR
(mbd_to_date BETWEEN  '$from_date' AND '$to_date')
OR
('$from_date' BETWEEN mbd_from_date AND mbd_to_date)
OR
('$to_date' BETWEEN mbd_from_date AND mbd_to_date)
)
*mbd=master_blocked_dates

Let me know if it doesn't work.

小开

Given two intervals like (s1, e1) and (s2, e2) with s1<e1 and s2<e2
You can calculate overlapping like this:

SELECT
s1, e1, s2, e2,
ABS(e1-s1) as len1,
ABS(e2-s2) as len2,
GREATEST(LEAST(e1, e2) - GREATEST(s1, s2), 0)>0 as overlaps,
GREATEST(LEAST(e1, e2) - GREATEST(s1, s2), 0) as overlap_length
FROM test_intervals

Will also work if one interval is within the other one.

小开

Recently I was struggling with the same issue and came to end with this one easy step (This may not be a good approach or memory consuming)-

SELECT * FROM duty_register WHERE employee = '2' AND (
(
duty_start_date BETWEEN {$start_date} AND {$end_date}
OR
duty_end_date BETWEEN {$start_date} AND {$end_date}
)
OR
(
{$start_date} BETWEEN duty_start_date AND duty_end_date
OR
{$end_date} BETWEEN duty_start_date AND duty_end_date)
);

This helped me find the entries with overlapping date ranges.

Hope this helps someone.

小开

You can cover all date overlapping cases even when to-date in database can possibly be null as follows: 

SELECT * FROM `tableName` t
WHERE t.`startDate` <= $toDate
AND (t.`endDate` IS NULL OR t.`endDate` >= $startDate);

This will return all records that overlaps with the new start/end dates in anyway.

小开

Mackraken's answer above is better from a performance perspective as it doesn't require several OR's in order to evaluate if two dates overlap. Nice solution!

However I found that in MySQL you need to use DATEDIFF instead of the minus operator -

SELECT o.orderStart, o.orderEnd, s.startDate, s.endDate
, GREATEST(LEAST(orderEnd, endDate) - GREATEST(orderStart, startDate), 0)>0 as overlaps
, DATEDIFF(LEAST(orderEnd, endDate), GREATEST(orderStart, startDate)) as overlap_length
FROM orders o
JOIN dates s USING (customerId)
WHERE 1
AND DATEDIFF(LEAST(orderEnd, endDate),GREATEST(orderStart, startDate)) > 0;

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