Consider the following Tiny college database $($primary keys are bold and underlined$)$:

Student $($StudentID$,$ lastname, firstname, email, major, earned points$)$

Course $($CourseCode$,$ title, description, credits, school$)$

Prerequisite $($CourseCode$,$ Prereq Code$)$

Class $($ClassCode$,$ sectiommumber$,$ starttime, endtime, CourseCode, LecturerID,SemesterCode$)$

Semester $($SemesterCode$,$ semesteryear, semesterterm$)$

Enroll $($StudentID ClassCode, grade$)$

Lecturer $($LecturerID$,$ lastname, firstname, email$)$

$=>$ grade $=$ weight of the letter grade $(A=4,B=3$dots$)$

$=>$ earned points grade $**$ credits