Normalize database up to the Third Normal Form


I am designing a database for the Film industry (personal exercise).

  • Each film was made by a company.
  • A company produces one or more movies.
  • Each film has one or more genres (action, terror, etc ...)
  • Each film has one or more actors.
  • Each film is directed by one or more directors (it is possible that a director act in a movie, including the one he is directing.)
  • Each movie has zero or more phrases spoken by an actor.
  • Each actor has a role in the film.

I still can not correctly identify the Dependencias Funcionales and the Dependencias Transitivas .

Original Table:

First Normal Form (1FN):

Second Normal Form (2FN):


I've been doing this until now ...

ER Model:

Diagram in SQL Server:

My questions are:

  • How do I identify which intermediate tables would be?
  • Trying to follow the rules I indicated above, how can I take my scheme to the Third Normal Form?
  • I am very confused, I hope you can help me, thanks in advance.

    asked by Robert Gomez 09.11.2017 в 20:14

    1 answer


    I think it could be an example like this:

    1.- Each film can have several genres:

    tabla_pelicula ------- > tabla genero-pelicula < -------- tabla genero

    • genero-pelicula
      • id_pelicula
      • id_genero

    In this way you can assign several genres to the same movie, which would only be related by the movie id and genre.

    You have to think about which table there may be of an element of the same table

  • Each film can have more than one actor and more than one director tabla actor -----> tabla película < -------- tabla director .
  • Here, yes, each table has its own primary id and they are related in the movie table.

    It's the same case for phrases.

  • You could relate to the actor with a phrase and in what film he said it:
  • tabla actor ---- > tabla frases < ------- tabla pelicula

    the table sentences if you should have a id principal since you will be adding data there as opposed to the genero-película table because that will only allow you to be relating a movie to your genre.

    answered by 09.11.2017 / 20:50