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Old 12-12-11, 13:56
njad njad is offline
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Old 12-12-11, 14:55
r937 r937 is offline
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1 yes

2 weak entity has a relationship where the FK is ~not~ part of the PK, but 1:N or M:N is determined by the entities themselves

3 yes

4 no, data attribute

5 not 1:N, rather N:1

6 book to author is M:N, article is not involved
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Old 12-12-11, 15:32
njad njad is offline
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Old 12-12-11, 20:02
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Old 12-12-11, 20:09
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Old 12-13-11, 12:07
Pat Phelan Pat Phelan is offline
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1) No. What?
4) Probably not.
5) No, see the r937's response
6) Correct.

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Old 12-13-11, 16:42
njad njad is offline
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Old 12-13-11, 16:44
r937 r937 is offline
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Quote:
Originally Posted by njad View Post
Is that means make relationship between publishers and books name it for example "publise_book"and make other between publishers and journals called "publish_journal"?
that sounds right
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Old 12-13-11, 17:43
njad njad is offline
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Old 12-14-11, 21:52
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Old 12-14-11, 23:29
Pat Phelan Pat Phelan is offline
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Quote:
Originally Posted by njad View Post
Hi ..
I want the ER diagram for these requirments:
"A bookstore database maintains information about books, professional journals, their authors and publishers. Books and journals are collectively referred to as publications that are published by publishers. All publications have a serial number (ISBN), a title and a year of publication. Books have an edition number whereas journals have a volume and number. No book or journal is published by more than one publisher. Journals contain articles. A book or an article can have one or more authors. Articles have a title and a subject category and no article can appear in more than one journal. Authors have a SSN, name and date of birth, whereas a publisher has a name and address." thanks ..
No problem, glad to have helped you!

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