CREATE TABLE `oauth_sessions` (
  `id` int(10) unsigned NOT NULL AUTO_INCREMENT,
  `client_id` varchar(255) CHARACTER SET ascii COLLATE ascii_bin NOT NULL,
  `scope` varchar(255) NOT NULL DEFAULT '',
  `nonce` varchar(255) CHARACTER SET ascii COLLATE ascii_bin NOT NULL,
  `user_id` int(10) unsigned DEFAULT NULL,
  `code` varchar(255) CHARACTER SET ascii COLLATE ascii_bin NOT NULL,
  `code_challenge` varchar(128) NULL,
  `code_challenge_method` enum('plain', 'S256') NULL,
  `token_claimed` tinyint(1) NOT NULL DEFAULT 0,
  `created` timestamp NOT NULL DEFAULT current_timestamp(),
  `expires` timestamp NOT NULL DEFAULT current_timestamp() ON UPDATE current_timestamp(),
  PRIMARY KEY (`id`),
  UNIQUE KEY `code` (`code`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_general_ci;

ALTER TABLE `oauth_tokens`
ADD `session_id` int(10) unsigned NULL,
ADD CONSTRAINT `oauth_tokens_session_id` FOREIGN KEY (`session_id`) REFERENCES `oauth_sessions` (`id`),
DROP INDEX `code`,
DROP INDEX `access_token`,
DROP `scope`,
DROP `nonce`,
DROP `user_id`,
DROP `code`,
DROP `access_token`;