abortIf($this->connection->getDatabasePlatform()->getName() !== 'postgresql', 'Migration can only be executed safely on \'postgresql\'.'); $this->addSql('DROP INDEX subscriptions.subscription_unique'); } public function down(Schema $schema): void { $this->abortIf($this->connection->getDatabasePlatform()->getName() !== 'postgresql', 'Migration can only be executed safely on \'postgresql\'.'); $this->addSql('CREATE UNIQUE INDEX subscription_unique ON subscriptions.subscriptions (author_id, subscriber_id)'); } }