code: public static List firstColumn(String query, Object... params) {
          return new DB(DB.DEFAULT_NAME).firstColumn(query, params);
      }
docs: This method returns entire resultset as one list. Do not use it for large result sets.
  Example:
  <pre>
  List ssns = Base.firstColumn("select ssn from people where first_name = ?", "John");
  for(Object ssn: ssns)
  System.out.println(ssn);
  </pre>
  
  This methods expects a query which selects only one column from a table/view. It will throw an exception if more than one
  columns are fetched in a result set.
  
  @param query raw SQL query. This query is parametrized.
  @param params list of parameters for a parametrized query.
  @return entire result set corresponding to the query.