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  1. #1
    Join Date
    May 2009
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    1

    Normalization: is this considered 1NF?

    Hi guys,

    I'm new to the board, I was working on the process of Normalization and was wondering whether this database is in 1NF or not?

    I think it is, but I could be wrong. The database is based on tables similar to Netflix.
    Attached Thumbnails Attached Thumbnails test.jpg  

  2. #2
    Join Date
    Dec 2007
    Location
    London, UK
    Posts
    741
    A database is said to be in 1NF if it accurately models some relation schema, i.e: every table enforces at least one candidate key and every tuple requires exactly one value for each attribute. In SQL, nulls are sometimes permitted but there is no sound basis for saying that nullable tables conform to 1NF because nulls stray outside formal and consistent definitions of relations and normal forms.

  3. #3
    Join Date
    Apr 2002
    Location
    Toronto, Canada
    Posts
    20,002
    Quote Originally Posted by ianhollings
    ... wondering whether this database is in 1NF or not?
    no, because not every table has a PK

    also, the film-collection relationship looks like many-to-many in the diagram, and that will require an association/relationship table between them, in order to avoid another 1NF violation

    Last edited by r937; 05-09-09 at 04:13.
    rudy.ca | @rudydotca
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