addSql('ALTER TABLE subnet CHANGE next_server next_server VARCHAR(255) DEFAULT NULL, CHANGE boot_file_name boot_file_name VARCHAR(255) DEFAULT NULL'); } public function down(Schema $schema): void { // this down() migration is auto-generated, please modify it to your needs $this->addSql('ALTER TABLE subnet CHANGE next_server next_server VARCHAR(255) NOT NULL, CHANGE boot_file_name boot_file_name VARCHAR(255) NOT NULL'); } }