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  1. #1
    Join Date
    Apr 2015
    Posts
    5

    Advanced Modelling - Specialization Hierarchy questions

    Hi guys,

    My name is Ray. I am still not clear about a problem of specialization hierarchy design.

    First of all, can I have one supertype that has two subtype discriminators? For example, a CUSTOMER supertype could be BUSINESS or INDIVIDUAL customer, plus a CUSTOMER also could IN_STORE purchase the products or buy products ONLINE. Therefore, I want to have the a disjoint discriminator between CUSTOMER and the two subtypes BUSINESS and INDIVIDUAL, plus another overlapping discriminator between CUSTOMER and the two subtypes IN_STORE and ONLINE.

    Is it possible to implement this way?

    Also, you know that SQL developer only support disjoint discriminator, so how can I implement both disjoint and overlapping into SQL developer properly?

    Thanks for your help in advance, I'm really confused about those stuff.

  2. #2
    Join Date
    Jan 2007
    Location
    UK
    Posts
    11,434
    customers (customer_id, customer_type, name, etc)
    customer_types (customer_type)
    channels (channel)
    customer_channels (customer_id, channel)

    1 customer can only have 1 customer type (they are either a business or an individual).
    1 customer can purchase in many channels (they can shop both in store and/or online).

    Am I missing something?
    George
    Home | Blog

  3. #3
    Join Date
    Apr 2015
    Posts
    5
    Hi gvee,

    you are exactly right.

    1 customer can only have 1 customer type (they are either a business or an individual).
    1 customer can purchase in many channels (they can shop both in store and/or online).

    however, I would like to implement those rules into a specialization hierarchy with a disjoint hierarchy for the 1st rule and an overlapping hierarchy for the 2nd rule. That's why I am stuck.

    because according to what I have known, each entity supertype can just be either disjoint or overlapping hierarchy. In this case, I want to make the CUSTOMER entity contains both overlapping and disjoint.
    Last edited by trithanhnham; 04-01-15 at 10:19.

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