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  1. #1
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    Triple many to many relationship

    Friends, I am having difficulty creating a relationship of tables in a database.

    I have a table and another table technology company. For each technology has several companies,
    and for each company have different technologies. A many to many.
    I created a join table to resolve this issue, with two foreign keys.

    I have another table Product, and for each company I have several products, and for each technology I also have
    various products.

    Any help is welcome.

    Thank you.

  2. #2
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    What seems to be the problem?

    I never think in terms of tables. I always start with a UML class model for the database. In this case, you have a Product class that has a many to many association with a Technology Class and a many to many association with a Company class. When converting these associations to implement them in a relational database, each of the many to many associations needs to be represented by its own table, just like in your first case.
    Last edited by ruirib; 2012-04-30 at 19:02.

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    fabiobarreto10 (2012-05-01)

  4. #3
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    ruirib, thanks for respoding and help.

    I was a little confused by your explanation, but I think that maybe I just need to make a relationship
    a table for many technology products for the table.



    I'm confused, because I would do the record companies, technologies and products through cascading combobox.

    Thank you.

    ps: Sorry indiscretion, I saw that you are located in Portugal. Do you speak Portuguese?

  5. #4
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    In practical terms you will need a Technology_Products table and Company_Products table, besides your base Technology, Products and Company tables (of course you also have the Technology_Company table that I think you mentioned before).

    Fabio, I am Portuguese, so yes, do speak the language .

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    fabiobarreto10 (2012-05-01)

  7. #5
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    Obrigado. Vou tentar fazer como você me explicou.

    Eu sou brasileiro. Estou estudando inglês sozinho( mas ainda estou no básico, eu uso o tradutor do google).
    Last edited by fabiobarreto10; 2012-05-01 at 10:47.

  8. #6
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    Translating: Fabio just said he'll try to do as I suggested.

    Sorry, Fabio, for our global audience, we need to use English as the language when posting on the forum.


    P.S.: Eu percebi que é brasileiro . Temos de usar Inglês, aqui no fórum, para que todos os visitantes possam entender o que escrevemos . Boa sorte com o projecto.

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  10. #7
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    Yes, sorry.

  11. #8
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    Not a problem.

    If there are language issues, do drop me a PM and I will help with the translation as best as I can .

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    fabiobarreto10 (2012-05-01)

  13. #9
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    Ok, thank you.

  14. #10
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    ruirib, I managed to solve the problem of relations, in fact, I only need a one to many relationship table
    technology products for the table.
    Thank you for helping.

  15. #11
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    Where do I put the topic as solved?

  16. #12
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    There is no way to do that. You just said it was over .

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    fabiobarreto10 (2012-05-03)

  18. #13
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    ruirib, just do not understand the second sentence. the translation was not clear to me.

  19. #14
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    I meant that you said it was solved, so that pretty much does it .

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  21. #15
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    ok, now I understand. Thank you again.

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