Indicate the name of the parts without discount.
name of the part refers to p_name; without discount refers to l_discount = 0.0000
SELECT T3.p_name FROM partsupp AS T1 INNER JOIN lineitem AS T2 ON T1.ps_suppkey = T2.l_suppkey INNER JOIN part AS T3 ON T1.ps_partkey = T3.p_partkey WHERE T2.l_discount = 0.0000