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  1. #1
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    List business rules from ER diagram??

    I need to come up with a list of 12 business rules that can be deduced from the following ER Diagram. I am finding it hard, can anyone come up with any?

    Thanks,

    Convention:

    Dotted Line = Optional
    Dotted and Solid Line = Weak
    Attached Thumbnails Attached Thumbnails ER1.JPG  
    Last edited by cookpau01; 04-15-10 at 07:54.

  2. #2
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    Based on what you have learned so far, what can you tell us about that diagram?

  3. #3
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    Well I can tell you that there is a one to many relationship between degree program and Student which is a weak entity.
    There is then a many to many relationship between student and module which is an optional entity.

    So the business rule I have so far are:
    A student does not have to have a module
    Students can attend many modules
    Modules are made up of many students
    A student can only be on one degree course

  4. #4
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    Looks like a good start.
    What makes you say this?
    Quote Originally Posted by cookpau01 View Post
    Student which is a weak entity.

  5. #5
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    Because I am sure that the notation in the diagram of a mix of solid and dashed line means that it is a weak entity. Meaning that the entities very existence depends on another entity.

  6. #6
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    Well thats the convention that we have been using anyway

  7. #7
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    Ok - that is fine then. I would mention that is not the recognised definition of a weak entity.

    I think your business rules are fine so far. I am no lecturer or student so again you will have to fit this in to your definitions however to my mind you have defined the "complex" business rules first. I think you can decompose them in to several simpler business rules which your more complex rules will build on. Whaddaya think?

  8. #8
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    I agree, I think that is the bit that I am finding difficult to do.

  9. #9
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    Ignore the lines\ relationships. Whaddaya see?

  10. #10
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    Student
    Degree
    Module

  11. #11
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    So I suppose you could say:
    There is a selection of module
    There is a selection of degree programs
    There are many students

    ???????

  12. #12
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    Quote Originally Posted by cookpau01 View Post
    Student
    Degree
    Module
    I think these are the fundamental business units of the organisation you are modelling. Would you agree?

  13. #13
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    Yes they are

  14. #14
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    Ok - wanna restate your rules so far?

  15. #15
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    A student does not have to have modules
    Students can attend many modules
    Modules are made up of many students
    A student can only be on one degree program
    There are a selection of modules
    There are many students
    There are many degree programs

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