Explanation on Rails Associations - Rails 4

Question

i'm new to rails and your help and advise would be much appreciated as i am finding this challenging

Aim: i want the creator of the event to be able to select more than one user as hosts for a created event (just like how facebook allows the creator of a page to be be able to select users as admins of a created page). Is the below how my model and schema should be displayed?

i was aiming to build something like this image. Event1 i can select Ian & Jesse as hosts, Event2 i can also select Ian again as a host and select Emma

This is how i imagine it so far to be built (your guidance would be much appreciated):

models
user.rb
has_many events

event.rb
belongs_to user

host.rb
belongs_to user
has_many events

schema

users
name
email

events
title
address
user_id

hosts
user_id
event_id

Answer 1

Started writing this as a comment but realised it was getting too wordy.

your model is broken ... an event has many users .. it doesn't belong_to a single user.

What you have is a many to many relationship between users and events which needs resolving through a join table (aka associative/junction table). You have gone some way to resolving this with the hosts table though this goes against the rails convention.

What you want is something like:

models

user.rb

has_and_belongs_to_many :events

event.rb

has_and_belongs_to_many :users

and create a join table that references the two models

users table
  name
  email

events table
  title
  address

events_hosts table
  user_id
  event_id

The rails convention is for the join table to be named by joining the two names of the tables it is joining lexically ordered - i.e. events before hosts, concatenated together to give events_hosts.

Alternatively, you can also create a join model if you prefer:

EventHost

belongs_to :user
belongs_to :event

and modify the has_and_belongs_to_many to has_many :event_hosts in the other two models - the database schema will remain the same.