MySQL 8.0

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CREATE TABLE `test_table`(
    `id` INT PRIMARY KEY AUTO_INCREMENT,
    `user_id` INT,
    `start` INT,
    `end` INT
);
INSERT INTO `test_table` (user_id, start, end) 
SELECT '4', '1', '5' FROM DUAL 
WHERE NOT EXISTS (SELECT * FROM `test_table` 
      WHERE user_id = '4' AND end >= '1')
INSERT INTO `test_table` (user_id, start, end) 
SELECT '2', '1', '9' FROM DUAL 
WHERE NOT EXISTS (SELECT * FROM `test_table` 
      WHERE user_id = '2' AND end >= '1')
SELECT '4', '6', '13' FROM DUAL
WHERE NOT EXISTS (SELECT * FROM `test_table` 
      WHERE user_id = '4' AND end >= '6')


4
6
13


4
6
13


SELECT '4', '6', '13' FROM `test_table` 
WHERE NOT EXISTS (SELECT * FROM `test_table` 
      WHERE user_id = '4' AND end >= '6')


4
6
13


4
6
13

4
6
13


INSERT INTO `test_table` (user_id, start, end) 
SELECT '4', '6', '13' FROM DUAL 
WHERE NOT EXISTS (SELECT * FROM `test_table` 
      WHERE user_id = '4' AND end >= '6')
SELECT '4', '11', '17' FROM `test_table` 
WHERE NOT EXISTS (SELECT * FROM `test_table` 
      WHERE user_id = '4' AND end >= '11')
INSERT INTO `test_table` (user_id, start, end) 
SELECT '4', '11', '17' FROM DUAL 
WHERE NOT EXISTS (SELECT * FROM `test_table` 
      WHERE user_id = '4' AND end >= '11')
SELECT * FROM `test_table`


id
user_id
start
end


1
4
1
5

2
2
1
9

3
4
6
13


INSERT INTO `test_table` (user_id, start, end) 
SELECT '4', '14', '17' FROM DUAL 
WHERE NOT EXISTS (SELECT * FROM `test_table` 
      WHERE user_id = '4' AND (start <= 14 AND end >= 14 OR start <= 17 AND end >= 17))
SELECT * FROM `test_table`


id
user_id
start
end


1
4
1
5

2
2
1
9

3
4
6
13

4
4
14
17