Okay. So this is what I've done as you see,
it looks a little nicer than it was before. And I didn't
really change that much. I just made a few changes, so
I just wanted to point them out to you, so that you
know what they are. And the main thing, one of the
main things I did is really to introduce these derived attributes. So
these are attributes that are basically
computed. Based on some other attributes.
Okay, they don't have a value themselves, but their value is computed.
And I used two. The first one is age. So
basically we know the age of the patron based on
the birthday, of the patron. So you guys, I don't
know if you have that information currently in the system.
>> No, we'll have to add that to the
form patrons fill out, when they get their card.
>> Is that, that an issue? Can you do it?
>> No yes, we, we can easily do that.
>> Okay, so then, perfect. So we'll do it that way. I think it's
a, in a little cleaner. And similarly, since you told me that the fine
was computed based on the amount of days that an
item was late. The patron was late returning the item, then I
also added this as a derived attribute that is computed based on
the due date and when the item is actually returned.
>> Makes sense.
>> Makes sense? Okay. And the rest
is kind of really minor things. So the, the only one I
want to point out is I didn't, you know, discuss that with
you before, but I added this, which is called cardinality
for some of these relationships. And what they say is basically
is how many elements are involved in the relationship.
>> So, you mean the stars?
>> Yeah, like the stars and the one...
>> Okay.
>> Here for example, this is telling you that for each item there
is only one title. And that for each title, there are multiple items.
>> So, star means many.
>> Stars mean many, yeah.
>> Okay, go you.
>> Sorry that's kind of computer science lingo - we use the star
for that kind of stuff. And, similarly, for the patron, it's
telling me that, you know, each patron can have multiple, can
request multiple titles, and that the same title can be requested
by multiple patrons, which I think is the way the system works.
>> Right. So except for these minor changes,
we already had a pretty good model in our hands, so
I think is a, we can finalize this and then just
move to the low level design and then implementation, and be
done with the system.
>> Sounds good.