RENAME TABLE `journal` TO `oldJournal`;

CREATE TABLE `journal` (
  `journalId` bigint(20) NOT NULL AUTO_INCREMENT,
  `currentIssueId` bigint(20) NOT NULL,
  `journalKey` varchar(255) CHARACTER SET utf8 COLLATE utf8_bin NOT NULL,
  `eIssn` varchar(255) CHARACTER SET utf8 COLLATE utf8_bin NOT NULL,
  `imageArticleId` bigint(20) DEFAULT NULL,
  `title` varchar(500) CHARACTER SET utf8 COLLATE utf8_bin NOT NULL,
  `created` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
  `lastModified` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  PRIMARY KEY (`journalId`),
  KEY `journal_ibfk_1_idx` (`currentIssueId`),
  CONSTRAINT `fk_journal_1` FOREIGN KEY (`currentIssueId`) REFERENCES `issue` (`issueId`),
  CONSTRAINT `fk_journal_2` FOREIGN KEY (`imageArticleId`) REFERENCES `article` (`articleId`)
);

RENAME TABLE `journal` TO `oldJournal`;

CREATE TABLE `journal` (
  `journalId` bigint(20) NOT NULL AUTO_INCREMENT,
  `currentIssueId` bigint(20) DEFAULT NULL,
  `journalKey` varchar(255) CHARACTER SET utf8 COLLATE utf8_bin NOT NULL,
  `eIssn` varchar(255) CHARACTER SET utf8 COLLATE utf8_bin NOT NULL,
  `imageArticleId` bigint(20) DEFAULT NULL,
  `title` varchar(500) CHARACTER SET utf8 COLLATE utf8_bin NOT NULL,
  `created` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
  `lastModified` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  PRIMARY KEY (`journalId`),
  KEY `journal_ibfk_1_idx` (`currentIssueId`),
  CONSTRAINT `fk_journal_1` FOREIGN KEY (`currentIssueId`) REFERENCES `issue` (`issueId`),
  CONSTRAINT `fk_journal_2` FOREIGN KEY (`imageArticleId`) REFERENCES `article` (`articleId`)
);

Tweak schema so that currentIssueId is nullable
Tweak schema so that currentIssueId is nullable

This was just a business logic bug; current issues aren't required.
