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  1. #1
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    artist is songwriter and or intrepret of song?

    hi,


    in a music database there are artist who can be songwriter and/or interpret of a song

    how would you design this only using binary relations?

    we got:
    artist
    song

    as tables i guess, but now i would create a
    artist - is songwriter of - song

    and
    artist - is intrepret of - song

    how to combine these two?

  2. #2
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    One song can have many songwriters
    One songwriter can have many songs
    Therefore this is a many-to-many relationship

    One song can have many artists
    One artist can have many songs
    Therefore this is a many-to-many relationship

    You do not want to combine these entities, you need two separate tables to manage each role.
    George
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  3. #3
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    ah, forgot to write that i was interrested in the ER diagramm for this case.

    your tables make sense, but i dont know how to represent that as ER.

    any tips?

  4. #4
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    also bear in mind a song may be performed by multiple performers who may also be song writers. given the nature of 'feats' and covers a perfomrer may appear on lots of different individual tracks. a song exists in its own right, but there may well be multiple different performers of that same song

    songwriters may be composers or lyricists or both or, as in the case of the the Verve's "Bittersweet Symphony" neither
    I'd rather be riding on the Tiger 800 or the Norton

  5. #5
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    Quote Originally Posted by stephen.meier View Post
    ah, forgot to write that i was interrested in the ER diagramm for this case.

    your tables make sense, but i dont know how to represent that as ER.

    any tips?

    Oh I see
    Why don't you draw up what you have so far and then we can give you pointers.
    George
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  6. #6
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    i would draw it like this:
    https://www.dropbox.com/s/v4lo5wx1pb...2018.59.15.jpg


    but somehow this "feels" wrong

  7. #7
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    double post, deleted
    Last edited by stephen.meier; 06-18-14 at 18:17.

  8. #8
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    someone has to enable my link....this may sake some time, sorry.

  9. #9
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    What you've drawn is all onene relationships
    George
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  10. #10
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    if it were me Id probably be looking at something like:-

    An Artist may have one or more roles (as a composer, lyricist, musician [and if you wanted to you could break down roles further eg Musician:- lead guitar, Musician:- Keyboards) producer and so on)
    A composition has one or more artists who composed it
    A composition may be recorded (performed) one or more times my different performers (eg cover versions, or re worked lyrics)
    A recording artist may have one or more roles in anyone recording/performance eg producer, performer and so on

    but as ever with this sort of homework it depends on what your briefing is, how close to the real world should your model be
    Attached Files Attached Files
    I'd rather be riding on the Tiger 800 or the Norton

  11. #11
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    the description makes sense, but i havent seen that notation yet.

    could you draw that in a chen like notation? that would be great

    its not supposed to be like the real world, just simple.
    also a link where this kind of problem is described and solved would be great, i havent found this problem with google yet.
    Last edited by stephen.meier; 06-19-14 at 10:17.

  12. #12
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    Stephen, can you put a little more effort in to your homework, please?
    George
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  13. #13
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    google isn't the only source

    could you draw that in a chen like notation? that would be great
    no I wont draw it in chen or any other notation, Im actually surprised I even got as far as fleshing out a design in SQL Arcitect.

    if you cant do your own coursework then you need to approach your teacher/lecturer, and or follow up the references they suggest you read

    a link to a solution, well no, its down to you how you design and develop your own model. the reality is that for coursework you have to do both. you have to go down the process and work out what works, develop your ideas.. learn by doing, not being given....
    I'd rather be riding on the Tiger 800 or the Norton

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