I am creating a relational database - a library management system. I want to show an example where I normalize the data from 2NF to 3NF. My example of 2NF looks like

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The definition of third normal form would be: 'all non-key attributes are not dependent on any other non-key attributes.'

In this instance, the non-key attribute ISBN determines the value of the primary key SKU (stock keeping unit). Does this define a transitive dependency, when SKU is the primary key?

And further, would it be correct to divide the uploaded table into a subtable (Book) with the attributes (isbn, title, author_first_name, author_middle_name, author_last_name) and the subtable (Copy) with the attributes (sku, isbn)?

  • No, because title and author info are dependent on the isbn...You need a separate books table with the book info. – JNK Apr 15 '15 at 19:56
  • @Emilie, According to your sample data ISBN does NOT determine SKU. There are 3 different SKUs for a single ISBN. If ISBN->SKU and SKU is a key then ISBN must be a key as well. In that case there would be no violation of 3NF. – nvogel Apr 16 '15 at 14:59

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