Subquery and SUM - mysql

Question

In need of help i have a question SQL statement that retrieves the maximum "Total Room Cost" in a hotel chain. And use a subquery to determine the total room cost grouped by hotel.. I can sort of do the 2 querys but i keep getting errors putting them together. my two tables. hotel--with table hotel_no and hotelname. room--with table room_no,hotel_no,room_type,room_price
So far i have
SELECT hotelname, SUM(room_price) as Total
FROM hotel, room
WHERE hotel.hotel_no = room.hotel_no
GROUP BY Hotelname
Gives me Hotel name and each hotel price
and
SELECT SUM(room_price) AS Total
FROM room
Gives me Total
every time i try to put them together i get an error
eg
SELECT hotel_no, SUM(room_price) AS "Total"
FROM room
WHERE hotel_no= hotel_no
UNION ALL
SELECT hotel_no, hotelname
FROM hotel
WHERE hotelname = hotelname
group by hotelname;
Please help Thx
Sry to be a pain but Apparently it got the right answer but i was wrong it has to be a subquery in the from
Question at this Hotel, every hotel in the chain has numerous rooms at various costs, The Hotel wants to know which hotel has the highest room cost total
Sample
SELECT MAX(SubFromName.NewColumnName)
FROM (SELECT columnName, SUM(columnName) AS ‘NewColumnName’
FROM table
GROUP BY columnName) SubFromName;
Hope this link works this is the schema data http://www.sqlfiddle.com/#!9/48429
The closest i have is below but still not right
select hotelname, MAX(room_price), SUM(room_price) AS 'Total Room Cost'
from room,hotel
WHERE hotelname IN (SELECT hotelname FROM hotel
WHERE hotel.hotel_no = room.hotel_no)
group by hotelname;
Cant have join or union should be like the sample If anyone gets what i mean Thankyou in advance. Im having a brain dead week.

Answer 1

Select chain_name, sum(price)
From chain a
Inner join
(Select a.hotel_no, sum(room_price) as price, b.chainid
From room a
Inner join hotel b
On a.hotel_no = b.hotel_no
Group by a.hotel_no) b
On a.Id =b.chainid
Group by chain_name

Answer 2

Try this:
SELECT hotel_no, SUM(room_price) AS Total, "" as hotelname
FROM room
WHERE hotel_no= hotel_no
UNION ALL
SELECT hotel_no, "" AS Total, hotelname as hotelname
FROM hotel
WHERE hotelname = hotelname
group by hotelname;
UNION ALL should have same number of columns in both queries.

Answer 3

Just to answer myself this is what i ended up with which worked
SELECT hotelname,
(SELECT SUM(room_price) from room where hotel_no = hotel.hotel_no) as TotalRoomCost
from hotel
GROUP BY hotelname
it was ment to be this
SELECT MAX(Eagle.TotalRoomCost)
FROM (SELECT hotel_no, SUM(room_price) AS 'TotalRoomCost' FROM room GROUP BY hotel_no) Eagle;