MariaDB [esportal]> show create table matchmaking_match;

+-------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+

| Table             | Create Table                                                                                                                                                                                                                                              |

+-------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+

| matchmaking_match | CREATE TABLE `matchmaking_match` (

  `id` bigint(20) unsigned NOT NULL AUTO_INCREMENT,

  `region_id` tinyint(1) unsigned NOT NULL,

  `inserted` int(10) unsigned NOT NULL,

  PRIMARY KEY (`id`)

) ENGINE=InnoDB AUTO_INCREMENT=47381 DEFAULT CHARSET=utf8 |

+-------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+

1 row in set (0.00 sec)

MariaDB [esportal]> show create table matchmaking_match_users;

+-------------------------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+

| Table                   | Create Table                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |

+-------------------------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+

| matchmaking_match_users | CREATE TABLE `matchmaking_match_users` (

  `matchmaking_match_id` bigint(20) unsigned NOT NULL,

  `user_id` int(10) unsigned NOT NULL,

  `team` tinyint(1) unsigned NOT NULL,

  `accepted` tinyint(1) unsigned NOT NULL DEFAULT 0,

  PRIMARY KEY (`matchmaking_match_id`,`user_id`),

  UNIQUE KEY `mmu_user_id` (`user_id`),

  CONSTRAINT `matchmaking_match_users_ibfk_1` FOREIGN KEY (`matchmaking_match_id`) REFERENCES `matchmaking_match` (`id`) ON DELETE CASCADE ON UPDATE CASCADE,

  CONSTRAINT `matchmaking_match_users_ibfk_2` FOREIGN KEY (`user_id`) REFERENCES `users` (`id`) ON DELETE CASCADE ON UPDATE CASCADE

) ENGINE=InnoDB DEFAULT CHARSET=utf8 |

+-------------------------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+

1 row in set (0.00 sec)

MariaDB [esportal]> select * from matchmaking_match_users where matchmaking_match_id not in (select id from matchmaking_match);

+----------------------+-----------+------+----------+

| matchmaking_match_id | user_id   | team | accepted |

+----------------------+-----------+------+----------+

|                45220 |  11179195 |    2 |        1 |

|                45220 |  16004445 |    1 |        1 |

|                45220 |  17375835 |    2 |        1 |

|                45220 |  19416596 |    2 |        1 |

|                45220 |  36791488 |    1 |        0 |

|                45220 |  42131544 |    1 |        1 |

|                45220 | 299652215 |    1 |        0 |

+----------------------+-----------+------+----------+

7 rows in set (0.00 sec)

MariaDB [esportal]> delete from matchmaking_match_users where matchmaking_match_id not in (select id from matchmaking_match);

Query OK, 7 rows affected (0.00 sec)

MariaDB [esportal]>