mysql之查询两个时间段是否有交集的情况

SELECT * FROM test_table
WHERE
    (start_time >= a AND start_time <= b)
    OR (start_time <= a AND end_time >= b)
    OR (end_time >= a AND end_time <= b) 

SELECT * FROM test_table
WHERE
    NOT (
        (end_time < a
        OR (start_time > b)
    ) 

drop table if EXISTS `test_date`;
CREATE TABLE `test_date` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `room_id` int(11) DEFAULT NULL COMMENT '房间id',
  `start_time` datetime DEFAULT NULL COMMENT '房态开始时间',
  `end_time` datetime DEFAULT NULL COMMENT '房态结束时间',
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;
INSERT INTO `test`.`test_date`(`id`, `room_id`, `start_time`, `end_time`) 
VALUES (1, 1, '2020-05-20 15:00:00', '2020-05-22 12:00:00');
INSERT INTO `test`.`test_date`(`id`, `room_id`, `start_time`, `end_time`) 
VALUES (2, 1, '2020-05-25 15:00:00', '2020-05-27 12:00:00');
-- 查询入住时间
set @s = '2020-05-18 23:59:59';
-- 查询离店时间
set @e = '2020-05-21 00:00:00';
-- 这个sql查询出来的话，是不合适的数据，有重叠
select * from test_date
where 
(start_time <= @s and end_time >= @s)
or
(start_time <= @e and end_time >= @e)
or
(start_time >= @s and end_time <= @e)
or
(start_time <= @s and end_time >= @e);
-- 这个sql不加反，求出来的是合适的数据，不重叠的数据
-- 取反，就是重叠的数据,日期不符合规范的数据，有相交的数据
select * from test_date
where
!(start_time >= @e or end_time <= @s);