Rails 1 to 1 relationship migration

Question

I'm new to rails. I have 2 existing models that I want to establish a 1 to 1 relationship.

class User
  has_one :info

class Info
  belongs_to :user

My Question is do I need to create foreign keys for each of them? My end goal is to just access info via: @user.info.

No, only one table needs a foreign key, but you'll need some index on the database to enforce the 1-1 relationship, see here for e.g: https://stackoverflow.com/a/15284858/828193 — user000001, Mar 01 '19 at 17:52

score 1 · Answer 1 · answered Mar 01 '19 at 17:56

1

As the commenter said, no you don't. Only the belongs_to side needs a foreign key. Let me point you to the Rails guides for this particular issue, but more widely they're excellent resources for this type of information.

answered Mar 01 '19 at 17:56

smathy

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score 0 · Answer 2 · answered Mar 01 '19 at 21:03

Start with simple.

@user = User.new
@user.first_name = "john"
@user.save

info = @user.info
info.address = "Some address"
info.save

@user.reload

puts @user.info.address

PS: I really suggest to start with a few video tutorials and just repeat what people are doing in video

Rails 1 to 1 relationship migration

2 Answers2