Q:

SQL Update across Two different Tables in Microsoft Server Management Studio

Im new kind of new to SQL and im trying to get an update query across Two Tables. Specificly i got those two tables:
PERSON (name, surname, email, phone, adress_id, room_id)

and
ROOM (room_id, number_of_beds, house_id)

and i would like to update the person on room_id. I thought of a statement like:
UPDATE PERSON
SET room_id = room_id
FROM ROOM
INNER JOIN ROOM ON 
    room_id = room_id

My friend told me to use aliases for a better overview but i don't understand how to use those.
Would this statement work and how could i use aliases in the statement?

A:

update p--is an alias to person
set 
p.stuffyouwantset=r.stuffyouwant
from 
person p
join
room r
on p.room_id=r.room_id

