def process_query_string_band(report, element):
    """
    Read from jrxml queryString element and query a datasource.
    :param report: dictionary holding report information
    :param element:
    """
    sql_stmt = element.get('value')
    if sql_stmt is not None:
        sql_stmt = sql_stmt.strip()
        report['field_names'] = report['main_datasource'].execute_query(
            sql_stmt)
