dyingatmidnight 0 Junior Poster

Hi, I'm having a little trouble figuring out how to show some of my relationships in an ER diagram and was hoping for some help:


Authors(aID, aname, abio)
Books(bID, title, summary, quanity)
Format(fiD, formatType)
hasFormat(fID, ISBN)
bookFormat(bID, fID)
libraryBook(libRef, bID)
Section(sectionId, sectionName)
Cardholders(cardNum, cname)
Address(addID, streetName, City, PostalCode)
cardholderAddress(cardNum, addID)
publisherAddress(pid, addID)
PhoneNumbers(phoneID, typeID, number)
PhoneType(typeID, numberType)
cardholderPhone(cardNum, phoneID)
publisherPhone(pid, phoneID)
Series(serID, title)
Status(sid, status)
Publishers(pID, name)
Checkout(libref, cardNum, checkoutdate, checkindate)
areInSection(libref, sectionID)
areInSeries(libref, serID, volumeNum)
areAvailable(libref, sid)
authorsWrite(aid, libref)
booksPub(libref, pid, year)
authorsPub(aid, pid)

The two causing me trouble are hasFormat(fID, ISBN) and libraryBook(libRef, bID). The problem is it's non a relationship between two tables so much as it is.... I fail with words. But it makes sense when I look at... just not when trying to diagram it

...and this is what happens when I try to think so eariler in the morning, if I add a table for the library reference numbers and a table for the ISBN's then it makes more sense

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