public function unmigrate($migrationName) {
		$this->createTable();
		$this->db->dal()->from('_migrations')->where('name', $migrationName)->delete();
	}
public function unmigrate($migrationName) {
		$this->createTable();
		$this->db->dal()->from('_migrations')->where('name', $migrationName)->delete();
	}
public function unmigrate ( $ migrationName ) { $ this -> createTable ( ) ; $ this -> db -> dal ( ) -> from ( '_migrations' ) -> where ( 'name' , $ migrationName ) -> delete ( ) ; }
Mark a migration as unmigrated.
@param  string $migrationName
Mark a migration as unmigrated .