I'm just starting out learning databases with SQLServer as the backend, but I've got some very basic UML questions.
In regards to a Library database, how would you properly show the relation between a User and the Items they borrow?
Say 1 user, at any one time, can borrow up to 3 items, is this correct?
Or in the UML diagram, would the BorrowTable be shown as an Association, like the latter example?
In the BorrowTable, would it require it's own Primary Key like I have there, or would the combination of the foreign keys UserID + Barcode be enough to form a unique key? Though what happens if a user re-borrows the same book (or do we typically wipe this kind of BorrowTable association/intermediary upon returning the books)?
Maybe a history table of borrowed items would form another table elsewhere, either off the User table, or off the CatalogItems table that keeps a record of which users have borrows x item.
Sorry, exceptionally new to all this. Happy and eager to read any documentation you want to throw my way.