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-   -   Can you please check my ER Diagram? (http://www.daniweb.com/forums/thread156390.html)

scottyscotty19 Nov 12th, 2008 10:18 am
Re: Can you please check my ER Diagram?
 
Each member of staff is only able to teach certain modules or even certain sessions of certain modules. Members of staff have line-mangers who report to the head of department

For some reason this was missing from the original I don't know why. Only just noticed that's the only thing missing.

scottyscotty19 Nov 12th, 2008 2:06 pm
Re: Can you please check my ER Diagram?
 
1 Attachment(s)
I tired to take on board everything that you said and this is what I come up with.

timothybard Nov 12th, 2008 2:37 pm
Re: Can you please check my ER Diagram?
 
What is the difference between the lecture entity and the session entity; isn't a lecture just a type of session? Same with practical session and session.

I see you removed the relationship between student and module. What was your reason for removing it?

You have the lectures entity joined to the semester entity; for my diagram, I was assuming that each session/lecture was the same regardless of the semester it was in.

Is the head of the department one of the tutors? If so, you need a relationship from the head of department to directly to the tutors entity.

I would also recommend looking at the direction of some of your relationships again.

Lastly, you need a way to track prerequisites and the level of each course and module.

scottyscotty19 Nov 12th, 2008 2:54 pm
Re: Can you please check my ER Diagram?
 
I am so confused now I don’t know why I removed it I guess I just kind of panicked and thought I didn’t need it thanks for pointing it out it will go back in.

It doesn’t state that a tutor is the head of department but it would make sense so I will add a link from head of dept. to tutors.

The directions of some of relationships I find really hard to figure out I have changed a few entities around but it again doesn’t seem right.

What is the difference between the lecture entity and the session entity; isn't a lecture just a type of session?

Again you are right I don’t need them I don’t have a clue why I thought I did I guess it’s because the deadline is approaching and I am struggling to get 18 tables. They will go. Thanks

scottyscotty19 Nov 12th, 2008 5:16 pm
Re: Can you please check my ER Diagram?
 
I started from scratch and listed the basic tables that I could find. I then decided that between all the tables there are many to many relationships so I did this:

student
student/course
Course
Course/module
Module
module/staff
staff
staff/lecture
lecture
lecture/practicalsession
practicalsession
practical/room
room/facilities
facilities
facilities/module

It makes sense to me because I have broke up all the many to many relationships what do you think?

scottyscotty19 Nov 12th, 2008 6:18 pm
Re: Can you please check my ER Diagram?
 
I give up thanks for your time timothybard your advice was really good I just struggled to get to terms with database design.

timothybard Nov 12th, 2008 7:09 pm
Re: Can you please check my ER Diagram?
 
You still need a Student/Module table and tables to deal with the prerequisites.

scottyscotty19 Nov 12th, 2008 8:46 pm
Re: Can you please check my ER Diagram?
 
That's cleared everything up Thanks timothybard.


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