<?php namespace Application\Migrations; use Doctrine\DBAL\Schema\Schema; use Wallabag\CoreBundle\Doctrine\WallabagMigration; /** * Changed tags to lowercase. */ class Version20170719231144 extends WallabagMigration { public function up(Schema $schema) { $this->skipIf('sqlite' === $this->connection->getDatabasePlatform()->getName(), 'Migration can only be executed safely on \'mysql\' or \'postgresql\'.'); // Find tags which need to be merged $dupTags = $this->connection->query(' SELECT LOWER(label) AS lower_label FROM ' . $this->getTable('tag') . ' GROUP BY LOWER(label) HAVING COUNT(*) > 1' ); $dupTags->execute(); foreach ($dupTags->fetchAll() as $duplicates) { $label = $duplicates['lower_label']; // Retrieve all duplicate tags for a given tag $tags = $this->connection->executeQuery(' SELECT id FROM ' . $this->getTable('tag') . ' WHERE LOWER(label) = :label ORDER BY id ASC', [ 'label' => $label, ] ); $first = true; $newId = null; $ids = []; foreach ($tags->fetchAll() as $tag) { // Ignore the first tag as we use it as the new reference tag if ($first) { $first = false; $newId = $tag['id']; } else { $ids[] = $tag['id']; } } // Just in case... if (\count($ids) > 0) { // Merge tags $this->addSql(' UPDATE ' . $this->getTable('entry_tag') . ' SET tag_id = ' . $newId . ' WHERE tag_id IN (' . implode(',', $ids) . ') AND entry_id NOT IN ( SELECT entry_id FROM (SELECT * FROM ' . $this->getTable('entry_tag') . ') AS _entry_tag WHERE tag_id = ' . $newId . ' )' ); // Delete links to unused tags $this->addSql(' DELETE FROM ' . $this->getTable('entry_tag') . ' WHERE tag_id IN (' . implode(',', $ids) . ')' ); // Delete unused tags $this->addSql(' DELETE FROM ' . $this->getTable('tag') . ' WHERE id IN (' . implode(',', $ids) . ')' ); } } // Iterate over all tags to lowercase them $this->addSql(' UPDATE ' . $this->getTable('tag') . ' SET label = LOWER(label)' ); } public function down(Schema $schema) { throw new SkipMigrationException('Too complex ...'); } }