MySQL 8.0

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CREATE TABLE `Users` (
  `id` bigint unsigned NOT NULL AUTO_INCREMENT,
  `name` varchar(256) CHARACTER SET utf8 COLLATE utf8_unicode_ci DEFAULT NULL,
  `createdAt` datetime NOT NULL,
  `updatedAt` datetime NOT NULL,
  PRIMARY KEY (`id`),
  UNIQUE KEY `users_id` (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=257 DEFAULT CHARSET=utf8mb3 COLLATE=utf8_unicode_ci;

INSERT INTO `Users` (`id`, `name`, `createdAt`, `updatedAt`) VALUES (1, 'Maria', '2021-07-11 00:51:36', '2021-07-11 18:09:58');
INSERT INTO `Users` (`id`, `name`, `createdAt`, `updatedAt`) VALUES (2, 'Peter', '2021-07-11 00:51:36', '2021-07-11 18:09:58');
INSERT INTO `Users` (`id`, `name`, `createdAt`, `updatedAt`) VALUES (3, 'Sonya', '2021-07-11 00:51:36', '2021-07-11 18:09:58');
INSERT INTO `Users` (`id`, `name`, `createdAt`, `updatedAt`) VALUES (4, 'Frank', '2021-07-11 00:51:36', '2021-07-11 18:09:58');
INSERT INTO `Users` (`id`, `name`, `createdAt`, `updatedAt`) VALUES (5, 'Johnny', '2021-07-11 00:51:36', '2021-07-11 18:09:58');

CREATE TABLE `Matches` (
  `id` bigint unsigned NOT NULL AUTO_INCREMENT,
  `userId1` int DEFAULT NULL,
  `userId2` int DEFAULT NULL,
  `createdAt` datetime NOT NULL,
  `updatedAt` datetime NOT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=5 DEFAULT CHARSET=utf8mb3 COLLATE=utf8_unicode_ci;

INSERT INTO `Matches` (`id`, `userId1`, `userId2`, `createdAt`, `updatedAt`) VALUES (1, 2, 5, '2021-07-12 21:57:31', '2021-07-12 21:57:31');
INSERT INTO `Matches` (`id`, `userId1`, `userId2`, `createdAt`, `updatedAt`) VALUES (2, 2, 3, '2021-07-12 21:57:31', '2021-07-12 21:57:31');
INSERT INTO `Matches` (`id`, `userId1`, `userId2`, `createdAt`, `updatedAt`) VALUES (3, 1, 2, '2021-07-12 21:57:31', '2021-07-12 21:57:31');
SELECT u1.*
FROM `Users` u1 
INNER JOIN `Users` u2 ON u1.id <> u2.id
LEFT JOIN `Matches` m ON (m.userId1, m.userId2) IN ((u1.id, u2.id), (u2.id, u1.id))
WHERE m.id IS NULL AND u2.id = 1


id
name
createdAt
updatedAt


3
Sonya
2021-07-11 00:51:36
2021-07-11 18:09:58

4
Frank
2021-07-11 00:51:36
2021-07-11 18:09:58

5
Johnny
2021-07-11 00:51:36
2021-07-11 18:09:58


SELECT u1.*
FROM `Users` u1 
INNER JOIN `Users` u2 ON u1.id <> u2.id
LEFT JOIN `Matches` m ON (m.userId1, m.userId2) IN ((u1.id, u2.id), (u2.id, u1.id))
WHERE m.id IS NULL AND u2.id = 2


id
name
createdAt
updatedAt


4
Frank
2021-07-11 00:51:36
2021-07-11 18:09:58


SELECT u1.*
FROM `Users` u1 
INNER JOIN `Users` u2 ON u1.id <> u2.id
LEFT JOIN `Matches` m ON (m.userId1, m.userId2) IN ((u1.id, u2.id), (u2.id, u1.id))
WHERE m.id IS NULL AND u2.id = 3


id
name
createdAt
updatedAt


1
Maria
2021-07-11 00:51:36
2021-07-11 18:09:58

4
Frank
2021-07-11 00:51:36
2021-07-11 18:09:58

5
Johnny
2021-07-11 00:51:36
2021-07-11 18:09:58


SELECT u1.*
FROM `Users` u1 
INNER JOIN `Users` u2 ON u1.id <> u2.id
LEFT JOIN `Matches` m ON (m.userId1, m.userId2) IN ((u1.id, u2.id), (u2.id, u1.id))
WHERE m.id IS NULL AND u2.id = 4


id
name
createdAt
updatedAt


1
Maria
2021-07-11 00:51:36
2021-07-11 18:09:58

2
Peter
2021-07-11 00:51:36
2021-07-11 18:09:58

3
Sonya
2021-07-11 00:51:36
2021-07-11 18:09:58

5
Johnny
2021-07-11 00:51:36
2021-07-11 18:09:58


SELECT u1.*
FROM `Users` u1 
INNER JOIN `Users` u2 ON u1.id <> u2.id
LEFT JOIN `Matches` m ON (m.userId1, m.userId2) IN ((u1.id, u2.id), (u2.id, u1.id))
WHERE m.id IS NULL AND u2.id = 5


id
name
createdAt
updatedAt


1
Maria
2021-07-11 00:51:36
2021-07-11 18:09:58

3
Sonya
2021-07-11 00:51:36
2021-07-11 18:09:58

4
Frank
2021-07-11 00:51:36
2021-07-11 18:09:58

id	name	createdAt	updatedAt
3	Sonya	2021-07-11 00:51:36	2021-07-11 18:09:58
4	Frank	2021-07-11 00:51:36	2021-07-11 18:09:58
5	Johnny	2021-07-11 00:51:36	2021-07-11 18:09:58

id	name	createdAt	updatedAt
1	Maria	2021-07-11 00:51:36	2021-07-11 18:09:58
4	Frank	2021-07-11 00:51:36	2021-07-11 18:09:58
5	Johnny	2021-07-11 00:51:36	2021-07-11 18:09:58