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Logical Data Model Help RRS feed

  • Question

  • Im a beginer data modeler and i have this problem:

    -products are sold on the basis of lease, or at a fixed price. The prices for these products can change from time to time.

    -The annual maintenance cost that the customer has to pay is 10% of the software product price if the customer is a domestic customer. Annual maintenance cost can change year to year. For international customer, the annual maintenance cost will vary based on which region in the world the customer is located. For software that is leased, there is flat pricing per year and per licence leased, and annual maintenance charge is not applicable.

    I have a customers entity, product entity, price entity with sub entities of lease price and fixed price. what would be a good way do model this problem? am i missing entities to relate this problem? Kidly appreciate your help!
    Tuesday, September 13, 2011 12:03 AM

Answers

  • Oh, high school, that's why you can read such small text. :) (In the future, a little larger please.)

    From the original post the Maintenance cost would seem to have a closer relationship with the product or region, here however, it doesn't get joined in until after the Customer is associated. Obviously Customer provides the region, but if it is based on region, why does the Customer entity need to be involved?

    I usually just do physical models, and lookups on top, so i don't understand everything about logical ERDs. What is the relationship between software product and product price? I see the chicken-feet on Product price, which makes me wonder.

    Nitpick: "Software Product" should likely just be "Software". As a deliverable, "Software" and "Product" mean the same thing, making it redundant.


    Wednesday, September 14, 2011 1:16 PM
    Answerer

All replies

  • Please send the existing table structure so that can be reviewed
    -- Reddy Balaji C. ##Mark as answer if it solves the issue
    Tuesday, September 13, 2011 10:00 AM
  • So far, it sounds like you are doing it right. To be sure though, the relationships between the objects must be reviewed. Do you have an ERD that you can post?
    Tuesday, September 13, 2011 12:09 PM
    Answerer
  •  

    Ok so this is the model i have developed so far. Also what are good books or websites to learn about this subjects, Im in high school and this is not taught at this level, thanks for your help!

    Tuesday, September 13, 2011 10:41 PM
  • Oh, high school, that's why you can read such small text. :) (In the future, a little larger please.)

    From the original post the Maintenance cost would seem to have a closer relationship with the product or region, here however, it doesn't get joined in until after the Customer is associated. Obviously Customer provides the region, but if it is based on region, why does the Customer entity need to be involved?

    I usually just do physical models, and lookups on top, so i don't understand everything about logical ERDs. What is the relationship between software product and product price? I see the chicken-feet on Product price, which makes me wonder.

    Nitpick: "Software Product" should likely just be "Software". As a deliverable, "Software" and "Product" mean the same thing, making it redundant.


    Wednesday, September 14, 2011 1:16 PM
    Answerer