<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def build_db_query(fields_names, field_values):
 """ method builds query dictionary by zipping together DB field names with the field values """

    if isinstance(field_values, string_types):
        field_values = [field_values]

    if len(fields_names) != len(field_values):
        raise ValueError('Error: unable to build a primary key query due '
                         'to mismatch in number of fields {0} vs {1}'
                         .format(len(fields_names), len(field_values)))

    query = dict()
    for k, v in zip(fields_names, field_values):
        query[k] = v
    return query