query: SELECT course_id FROM student_course_registrations WHERE student_id = 121 UNION SELECT course_id FROM student_course_attendance WHERE student_id = 121
question: Find id course which are registered or attended by student whose i d one 121?
query_toks: SELECT course_id FROM student_course_registrations WHERE student_id = 121 UNION SELECT course_id FROM student_course_attendance WHERE student_id = 121
query_toks_no_value: select course_id from student_course_registrations where student_id = value union select course_id from student_course_attendance where student_id = value
question_toks: Find id course which are registered or attended by student whose i d one 121?