The database keeps track of each student's name, SSN, current address & phone, permanent address & phone, birthdate, sex, class (freshman, sophomore, ......, master, phd), major department, college, major (a 4-char code). Some applications need to refer individually to the city, state (2-char abbrv.) and zip code (some use 5-digit, some use 9) of the students' address. Some applications need to refer to students' first and last names separately. SSN is unique to the student.

Each department has a name, a 3-char code, location (main building and room number), office phone, college, and a list of instructors. Department names are unique, even they are in the different colleges. Department codes are unique within the university.

Each instructor has his/her SSN, first name and last name.

The course catalog contains the list of courses which WMU offers. Each course has a number (e.g. 543), name, description, credit hours & department. Course numbers are unique within a department, but not unique across the university (so taken together, they are unique). Not every course is offered every semester.

Each section has a single instructor (first and last names - no team-taught class), semester (1-4), year (2-digit), course number and section number.

A grade report contains the student's name, SSN, course number & section, letter grade (A, BA, B, ..., E, X, I).

how do i write an ER diagram for this prob...i am not able to find a rln to the grade report...plz help me with this..

The Student's SSN is the RLN - use to access the a particular student's grade report - The grades would be a table - with the unique identifier or RLN (I think that is what you mean Relational number) being the student by SSN. Classes are identified by class number & department number (the unique identifier together in the class file) Or can be broken out to be identified by department & within that table of course instructors identified by their SSN. And so on... The instructor table with SSN for teacher being the primary key or unique identifier for the instructor table. Break it down by table - or think about it if you were doing it manually - how would you go to get a paper record - how would you file it? Department table would have of course the dept. number and the full department name. Same so with Student detail file SSN, Name of Student, address, and so on-
AND SO it goes....always remembering detail and within the detail an identifier that can relate ie. From Student detail is SSN that relates to the Grade table by SSN. The Instructor table relates to the Course table by Instructor SSN to get a report of the classes a particular instructor is teaching. The Course Table also Relates to the Grade Table by Class Number, Semester or QTR, year and so on. These are just examples... You need to practice to start thinking in this fashion - requires sitting down and breaking out the tables - and then relating - writing it down and seeing it - practice, practice, practice.. and you will soon start to think this way... still need to have the charts - because thinking on your feet , you can miss things