CREATE TABLE enroll (class_code CLOB, stu_num NUMBER, enroll_grade 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 class (class_code CLOB, crs_code CLOB, class_section CLOB, class_time CLOB, class_room CLOB, prof_num NUMBER)
CREATE TABLE course (crs_code CLOB, dept_code CLOB, crs_description CLOB, crs_credit NUMBER)
CREATE TABLE department (dept_code CLOB, dept_name CLOB, school_code CLOB, emp_num NUMBER, dept_address CLOB, dept_extension 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 professor (emp_num NUMBER, dept_code CLOB, prof_office CLOB, prof_extension CLOB, prof_high_degree CLOB)

Find the first names and offices of all instructors who have taught some course and the course description and the department name.
SELECT T2.emp_fname, T4.prof_office, T3.crs_description, T5.dept_name FROM class AS T1 JOIN employee AS T2 ON T1.prof_num = T2.emp_num JOIN course AS T3 ON T1.crs_code = T3.crs_code JOIN professor AS T4 ON T2.emp_num = T4.emp_num JOIN department AS T5 ON T4.dept_code = T5.dept_code
SELECT "T2"."emp_fname", "T4"."prof_office", "T3"."crs_description", "T5"."dept_name" FROM "class" "T1" JOIN "employee" "T2" ON "T1"."prof_num" = "T2"."emp_num" JOIN "course" "T3" ON "T1"."crs_code" = "T3"."crs_code" JOIN "professor" "T4" ON "T2"."emp_num" = "T4"."emp_num" JOIN "department" "T5" ON "T4"."dept_code" = "T5"."dept_code"