Re: Newbie needs help with E/R model

Originally posted by Rob
> I'm supposed to design a database for a movie rental shop using the
> Entity/Relationship model. Problem is, I have to use between 5 and 10
> entities, and between 10 and 20 relationships. I don't have any
> practice at this, and I'm finding it hard to think of enough entites
> and relationships. Here are the few
>
> Here are the entities I've managed to come up with, with their
> attributes listed.
>
> Movies:
> -sku (ID #)
> -title
> -year
> -price
> -format (i.e., vhs, dvd)
> -condition (i.e. rental, new for sale, used for sale)
> -genre
>
> Branch:
> -store ID#
> -phone no.
> -address
>
> Members:
> -account no.
> -name
> -address
> -phone no.
> -credit card no.
>
> Stars:
> -name
>
> I don't know how I could get closer to 10 entities. It took me long
> enough to come up with 5! Am I maybe giving each entity too many
> attributes?
>
> Here are the relationships I thougt of:
>
> rented(member, movie)
> memberOf(member, branch)
> starsIn(star, movie)
>
> I still need 7 relationships. Any help or hints are greatly
> appreciated!
> Rob
>
>
> StarsIn (movies, stars)

Hint: When did member 123 rent the movie "X-Men"?
Hint: Does branch 42 have "X-Men"?  How many copies?
Hint: When did Member 123 join Branch 42?

That's 3 more entities for a kick-off.

BTW, what is this "SKU" everyone uses in their tables these days? I'm getting old, and can't understand the modern lingo.

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