Entity Relationship Diagrams (Library Example)

[DJMK4]

Im trying to get my head around this, iv been pondering on this for a while now and not 100% sure if im on the right track.

Given the library system example with books and the loaning of these books, a customer can lend a book from a library, a library may contain several copies of the same book, but does this look right?

1)One customer can have many loans
2)Many Loans may feature 1 book
3)One Book may have many copies
4) One copy may have many reservations

Thing i have a problem with is the many loans may feature one book? also number 3, the book does not have many copies?

 

[DJMK4]

Ahh yeah thats better, i see the principal of it all now, ill stick it all in access and link up the key fields and see what i get.

Cheers

 

[DJMK4]

So to sum up

One customer can have many loans
Many Loans can contain one copy
One copy can contain many books
One Book can contain many reservations

?

 

[DJMK4]

Just tried plonking that in access and i still have an outstanding one-to-one relationship that i cannot make up.