def add_record(post_id, catalog_id, order=0):
        '''
        Create the record of post 2 tag, and update the count in g_tag.
        '''

        rec = MPost2Catalog.__get_by_info(post_id, catalog_id)
        if rec:
            entry = TabPost2Tag.update(
                order=order,
                # For migration. the value should be added when created.
                par_id=rec.tag_id[:2] + '00',
            ).where(TabPost2Tag.uid == rec.uid)
            entry.execute()
        else:
            TabPost2Tag.create(
                uid=tools.get_uuid(),
                par_id=catalog_id[:2] + '00',
                post_id=post_id,
                tag_id=catalog_id,
                order=order,
            )

        MCategory.update_count(catalog_id)
Create the record of post 2 tag, and update the count in g_tag.