Gets a list of all regions.

    :return: A list of all regions. Results have regionID and regionName.
    :rtype: list

def get_all_regions(db_connection):
    """ Gets a list of all regions.

    :return: A list of all regions. Results have regionID and regionName.
    :rtype: list
    """

    if not hasattr(get_all_regions, '_results'):
        sql = 'CALL get_all_regions();'
        results = execute_sql(sql, db_connection)
        get_all_regions._results = results

    return get_all_regions._results