def _dict_of_targetid(submitid, charid, journalid):
    """
    Given a target of some type, return a dictionary indicating what the 'some
    type' is. The dictionary's key will be the appropriate column on the Report
    model.
    """
    if submitid:
        return {'target_sub': submitid}
    elif charid:
        return {'target_char': charid}
    elif journalid:
        return {'target_journal': journalid}
    else:
        raise ValueError('no ID given')