CREATE TABLE class (class_code CLOB, crs_code CLOB, class_section CLOB, class_time CLOB, class_room CLOB, prof_num NUMBER)
CREATE TABLE department (dept_code CLOB, dept_name CLOB, school_code CLOB, emp_num NUMBER, dept_address CLOB, dept_extension CLOB)
CREATE TABLE student (stu_num NUMBER, stu_lname CLOB, stu_fname CLOB, stu_init CLOB, stu_dob TIME, stu_hrs NUMBER, stu_class CLOB, stu_gpa NUMBER, stu_transfer NUMBER, dept_code CLOB, stu_phone CLOB, prof_num NUMBER)
CREATE TABLE enroll (class_code CLOB, stu_num NUMBER, enroll_grade CLOB)
CREATE TABLE employee (emp_num NUMBER, emp_lname CLOB, emp_fname CLOB, emp_initial CLOB, emp_jobcode CLOB, emp_hiredate TIME, emp_dob TIME)
CREATE TABLE course (crs_code CLOB, dept_code CLOB, crs_description CLOB, crs_credit NUMBER)
CREATE TABLE professor (emp_num NUMBER, dept_code CLOB, prof_office CLOB, prof_extension CLOB, prof_high_degree CLOB)

What are the names of all students taking a course who received an A or C?
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'
SELECT "T1"."stu_fname", "T1"."stu_lname" FROM "student" "T1" JOIN "enroll" "T2" ON "T1"."stu_num" = "T2"."stu_num" AND ("T2"."enroll_grade" = 'A' OR "T2"."enroll_grade" = 'C')