problem in many to many relationship

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感情败类 2021-01-28 02:37

I have two tables jewelry(j_id,j_name,Description) and style(style_id,style_name,image) each table has a many to many relationship with the other table

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  • 2021-01-28 03:02

    Not sure that this is a database-design question. To me it looks more like a programming question and in that case it would be helpful to know what programming language and database you are using.

    Anyway here is some pseudo code that does what I think it is you are asking about.

    Add one row in table jewelry
    Store the new jewelry.j_id to a variable @jid
    
    for each @StyleID in SelectedStyleList
    begin
      Add one row to table jewelry_style 
       set jewelry_style.j_id=@jid, jewelry_style.style_id = @StyleID
    end
    
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  • 2021-01-28 03:20

    your question is not about designing your database for this many-to-many relationship but about the inserting strategy when creating new jewelry / style objects and relations between them?

    In that case your strategy has to be a transaction inserting your main data and after that relating each other. In case of abortion you can just rollback the transaction and everything you created is removed. As long as you're in a transaction and your isolation level is correct nobody will see the temporarily created data

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  • 2021-01-28 03:28

    I would recommend 4 tables, 3 for the jewellery and style and the fourth one for orders.

    Jewellery : jid (PKEY),jname,description

    Style: sid (PKEY), sname, description

    Product : pid (PKEY), sid(FKEY), jid(FKEY) - One Product defines a unique combination of style and kewellery

    Order : oid(PKEY), pid(FKEY), other details(name, address etc.)

    For each jewellery, recover associated styles using the product table and populate the fields on the html page. For each order, store the product id, which uniquely identifies both the jewellery and style.

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