This is actually only used for plots, but, of course, it means that
every booking now can potentially have many booked campsites, and have
to create a relation for it.
I now have a conundrum regarding stay dates: i need them to be in the
same table as the campsite_id, because constraints only work on a single
relation and without the dates i can not make sure that i am not
overbooking a given campsite; but, on the other hand, all campsites
under the same booking must be for the same dates.
Where does stay belong, then? In booking or booking_campsite? If in
booking then i can not have a constraint that most assuredly will bite
me in the back, but if in booking_campsite then each campsite could
potentially have different dates.
As far as i can see, i can not use a exclude constraint with <> for
dates in booking_campsite to ensure that all rows with the same
booking_id have the same stay (i.e., exclude those that have a different
stay for the same booking_id).
For now, the say is in **both** relations: in booking, because i need it
when it is a prebooking, at least, and in booking_campsite for the
aforementioned constraint requirements.
Will this come back and bite me? Yes, it will. But what can i do?
I need the campsite_id in booking to know what row to show the booking
at. Besides the need of knowing which actual campsite has been booked,
of course.
This field is nullable because we can not now it until an employee has
confirmed the booking; until that point we only know the campsite type
customer requested. I do not care much if the campsite_id is from a
different campsite_type, because maybe the customer requested the change
by phone or what have you, therefore the database can not be that
strict. It must have a value if the booking is confirmed.
It helps me if the arrival_date and departure_date is a single
daterange, because then i can use `&&` and other range operators to work
with these dates. For instance, i have to intersect it with the range
displayed on the screen in order to know which day i have to put it.
But then i have to know whether the booking begins and ends in the
display range, because i only have to show arrival and departure (i.e.,
the box half-way within the first or last boxes) on these days only.
This is required by law.
I do not know why i have this value and the tax amount in the database,
but the payment percent and the number of days are hardcoded. I guess i
am such an inconsistent mess.
It is a separate relation, instead of having a field in campsite_type,
because not all campsite types allow dogs. I could have added a new
field to campsite_type, but then its values it would be meaningless for
campsites that do not allow dogs, and a nullable field is not a valid
solution because NULL means “unknown”, but we **do** know the price —
none.
A separate relation encodes the same information without ambiguities nor
null values, and, in fact, removed the dogs_allowed field from
campsite_type to prevent erroneous status, such as a campsite type that
allows dogs without having a cost — even if the cost is zero, it has to
be added to the new relation.
Customer told us that the minimum number of nights is per campsite type,
not per season. And he wants this, along with the maximum number of
nights, in order to limit the range of departure dates that guests can
choose when booking.
jordi fita mas