Find names of all students who took some course and got A or C.
create table enroll (stu_num varchar, enroll_grade varchar, PRIMARY KEY (stu_num)); create table student (stu_fname varchar, stu_lname varchar, stu_num varchar, PRIMARY KEY (stu_fname))
select t1.stu_fname, t1.stu_lname from student as t1 join enroll as t2 on t1.stu_num = t2.stu_num where t2.enroll_grade = 'c' or t2.enroll_grade = 'a'