def get_id_by_name(tag_name, kind='z'):
        '''
        Get ID by tag_name of the label.
        '''
        recs = TabTag.select().where(
            (TabTag.name == tag_name) & (TabTag.kind == kind)
        )
        logger.info('tag count of {0}: {1} '.format(tag_name, recs.count()))
        # the_id = ''
        if recs.count() == 1:
            the_id = recs.get().uid
        elif recs.count() > 1:
            rec0 = None
            for rec in recs:
                # Only keep one.
                if rec0:
                    TabPost2Tag.delete().where(TabPost2Tag.tag_id == rec.uid).execute()
                    TabTag.delete().where(TabTag.uid == rec.uid).execute()
                else:
                    rec0 = rec

            the_id = rec0.uid
        else:
            the_id = MLabel.create_tag(tag_name)
        return the_id
Get ID by tag_name of the label.