Relationship model and entity

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Boy, I'm setting up a website that owns the artist chart and an artist can play more than one musical genre, how would I put the genres that the artist plays in the database?

    
asked by anonymous 02.10.2017 / 01:20

1 answer

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Here are the tables that I created to illustrate.

Please disregard the names, as I did a little running.

Here I create my artist table 

CREATE TABLE artistaMusica(
id_artista SERIAL,
nome VARCHAR(10),
 PRIMARY KEY(id_artista)
)

Here the genres 

CREATE TABLE generoMusica(
id_genero SERIAL,
nome_genero VARCHAR(20),
PRIMARY KEY(id_genero)
)

Here the table responsible for making the connection between the tables 

CREATE TABLE genero_artistaMusica(
id_artista INT,
id_genero INT,
CONSTRAINT pk_genero_artista_id_artista PRIMARY KEY(id_artista,id_genero),

 FOREIGN KEY (id_genero)
REFERENCES  generoMusica(id_genero),

  FOREIGN KEY (id_artista)
REFERENCES  artistaMusica(id_artista)

)

Some points:

  • The relationship that I created would be like this, an artist may have no or several genres, and a genre may have no or multiple artists.

  • So I created a composite Primary Key to avoid duplicate data, such that the same artist is inserted twice with the same genre.
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