How to model weak entity in ER diagram? I was going through the weak entity concepts and was trying to model the relation Hotel has many rooms. I have come up with the partial solution presented below but i'm having a problem to uniquely identify the tuples in the room entity related to the specific hotel.
My Assumption

Hotel(hotel_number, name) is a strong entity.
Rooms(room_number, bed) is a weak entity whose existence depends on the existence of the hotel.


1. Hotel entity's table




hotel_id
name




125
n1


132
n2


173
n3


103
n4


193
n5




2. Room entity's table




room_number
beds




101
3


101
2


102
1


103
6




There are two hotels with hotel_id 125 and 132. Hotel with hotel_id 125 has room numbered 101 with 3 beds and another hotel has room_number 101 with 2 beds. So how can i model the given relation in such condition as there's no pk for the weak entity i.e. room ??
Room should have PK of (hotel_id,room_number).
Weak entities have compound keys with the strong entity key/foreign key as the leading column(s).
There are people who disagree with this approach, but they are wrong.

How can i find the room belonging to specific hotel which has the different number of beds limiting the attributes in the domain of my problem

Something like:
select *
from rooms
where hotel_id  = 1001
  and beds = 3