code: public function createColumn()
      {
          if ($this->getColName()) {
              $this->tableManipulator->createColumn(
                  $this->getMetaModel()->getTableName(),
                  $this->getColName(),
                  $this->getSQLDataType()
              );
          }
      }
docs: Creates the underlying database structure for this field.
  
  You have to override this function in field types, when you want to have multi column structure etc.
  
  @return void