Creating a view with sums from multiple tables (Oracle SQL) - sql

Question

I'm trying to create a view that gets the sums of a couple of different rows in various tables. (I'm not sure how to explain this properly)
Here is how my tables are set out:
Visitors:
VISITORID FNAME LNAME PHONE HOTELID
---------- --------------- --------------- --------------- ----------
23 Bella Morgan 0394110625 3
Bookings:
BOOKINGID HOTELID ROOMNO BOOKINGDATE BOOKINGDAYS BEDANDBREA VISITORID
---------- ---------- ---------- ------------------- ----------- ---------- ----------
28 3 509 28-04-2013 00:00:00 3 Yes 23
Rooms:
ROOMNO HOTELID ROOMTYPE PRICE
---------- ---------- ------------------------- ----------
509 3 Double 700
Services:
SERVICEID SERVICENAME COST HOTELID
---------- -------------------------------------------------- ---------- ----------
1-CLTH Cloth Cleaning 14.95 1
2-RMSV Room Service 9.95 2
Booking_services:
SERVICEID BOOKINGID
---------- ----------
2-RMSV 32
1-CLTH 32
I want to create a view called bills that gives me the total of room cost and cost of all services.
To get the room price, the sum is rooms.price*bookings.bookingdays.
For the services, it's the sum of all the rows in the services table that match the SERVICEID in booking_services for the matching bookingID.
Currently there are more rows in all of the tables than I've shown (so it doesn't take up too much space on here) and I have a query but it's only showing 2 of the visitors that i'd like the total for. I know it's because of line 5, but I'm not sure how I can get it to calculate that as well as those who do not have a row in booking_services.
Here is that query:
CREATE VIEW bills AS
SELECT v.fname, SUM((r.price*b.bookingdays)+s.cost) AS total
FROM visitors v, rooms r, bookings b, services s, booking_services bs
WHERE v.visitorid = b.visitorid
AND
s.serviceid in(select bs.serviceid from booking_services where bs.bookingid = b.bookingid)
AND
b.roomno = r.roomno
GROUP BY v.fname;
Any help to get what I'm after (if this makes any sense) would be appreciated.

Answer 1

Here is the SQLFiddel Demo
You can try below query for your view:
Select v.fname, sum((r.price*b.bookingdays)+nvl(bso.cost,0))
From visitors v
Join bookings b
on v.visitorid = b.visitorid
Join rooms r
on b.roomno = r.roomno
left outer join (select bs.BOOKINGID,sum(cost) as cost
from booking_services bs
Join services s
on s.SERVICEID = bs.SERVICEID
group by bs.BOOKINGID) bso
on bso.BOOKINGID = b.BOOKINGID
GROUP BY v.fname;