What is the process for updating data from a 3-table join in a database?

What is the process for updating data from a 3-table join in a database? What is the flow for updating data from a 3-table join?
The tables are as follows:
User Table
Table 1
id_user
name
email
password
Room Table
Table 2
id_room
name_room
status_room
price
Rev Table Joined from User Table and Room Table
Table 3
id_rev
id_room
id_user
facility