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Thread: Please Advise

  1. #1
    Join Date
    Jan 2004
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    Please Advise

    Hi I have done a ER but when I started to decompose the relationship I got so many table that now I am not sure whether it is correcr.

    Please could you have a look ar it and say what you think?

    Some backgound
    (coursework) The database is for a Driving Licence Examination Organisation , this company will take candidates from an organisation an examine them for a specified type of Licence.



    Can_Add = Candidate Address same for Ex_Add = examiner Address.

    thanks for your time.
    The Prophet

    here is the picture http://www.profetas.greatnow.com/

  2. #2
    Join Date
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    The number of tables is not your problem.

    There appear to be some conceptual flaws in your model.
    Last edited by certus; 01-31-04 at 23:41.

  3. #3
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    Please tell me what

  4. #4
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    Your course assignment structure doesn't appear to work.

    Your examiner structure doesn't seem to work.

    Explain the relationships connected to Course.

    ie. One Course has One Examiner, One Examiner has Many Courses.

  5. #5
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    ho yes, because I thought that one course may be examined by many examiners, So I had many to many relationship.

    to decompose it (the table name may not be right) I created Examining.
    a group of examiner assigned to a examining team. the same for candidates. a course could have many candidates , a a candidate many course so, I created a intermidiate table, assigned candidates. is that right?

  6. #6
    Join Date
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    You've got your many to many relationships backwards.

    Course(CourseID, attributes)

    Examiner(ExaminerID,Attributes)

    CourseExaminer(CourseID,ExaminerID)

    1 Course has Many Course Examiners
    1 Examiner has Many Course Examiners.

    This is probably the same problem with Assign.

  7. #7
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    Yes but it is no longer many to many. now it is , many to one. I don't know.
    What would you do?

  8. #8
    Join Date
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    It is still many to many resolved with an associative entity.

    http://www.utexas.edu/its/windows/da.../refining.html
    Last edited by certus; 02-05-04 at 06:18.

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