select * from PX_PROMOTION where rownum < 2 order by PX_PROMOTION_ID Desc;
will return the complete promotion record for last created promotion -
select XMLPARAM from PX_PROMOTION where rownum < 2 order by PX_PROMOTION_ID Desc;
will return the xml only for the last created promotion
select * from PX_PROMOTION where PX_PROMOTION_ID=1234;
will return the promotion record for a respective promotion Id.