What is the last name of the student who got a grade A in the class with code 10018.
create table enroll (stu_num varchar, enroll_grade varchar, class_code varchar, PRIMARY KEY (stu_num)); create table student (stu_lname varchar, stu_num varchar, PRIMARY KEY (stu_lname))
select t1.stu_lname from student as t1 join enroll as t2 on t1.stu_num = t2.stu_num where t2.enroll_grade = 'a' and t2.class_code = 10018