def construct_set_string(phage_id_set):
    """Convert set of phage_ids to string formatted for MySQL.

    e.g. set: {'Trixie', 'L5', 'D29'}
    returns: "('Trixie', 'L5', 'D29')""
    """
    string = "('" + "', '".join(phage_id_set) + "')"
    return string
