If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

 
Go Back  dBforums > General > Database Concepts & Design > ER model aggregation problem

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #1 (permalink)  
Old 01-08-11, 06:03
vpetrovic vpetrovic is offline
Registered User
 
Join Date: Jan 2011
Posts: 1
ER model aggregation problem

Hello all!
This is my first message here, I hope i will get lucky
There is a ER model on a posted picture, and i have a problem with the last aggregation PrijavaPolaganja. Sorry for foreign language, but I have drawn this in Visio and lost the document
Kurs=Course; Profil=Profile; Program=Program ; Nastavnik=Teacher; Polaznik=Student; Angazovanje=CourseListForTeacher; IzborKurseva=CourseListForStudent;
PrijavaPolaganja is when student wants to pass the exam on particular Course that is on his lsit, and being tested by a Teacher that is on that Course.
In Program we have CourseID and ProfileID as key, and those "fields" are part of keys of two underlying aggregations (TeacherID,CourseID,ProfileID & StudentID,CourseID,ProfileID).
Is there any way that I can make the last aggregation possible to reflect those real life constraints? Student can pick a Course from his list and get tested by a Teacher that is on that Course in that particular Profile?
Attached Thumbnails
ER model aggregation problem-kursevi.jpg  
Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On