CODEWITHSUNDEEP
ruby-on-railsuuidrails-migrationsruby-on-rails-4
xph
xph

Reputation: 752

Rails 4.0 integer ID -> UUID / Add options hash to table in ActiveRecord Migration?

stackoverflow newbie here, although I've been on here many times to look for helpful answers in the past. This is my first question though, so please be nice :)

I've been trying to figure out how to change a table in an ActiveRecord Migration in Rails by adding (or modifying) the options hash that comes with the create_table command. More specifically, I'm trying to convert a model that uses integer IDs into one that uses UUIDs in Rails 4.0 and postgresql 9.1.9.

So for example, my schema currently looks like this:

create_table :users do |t|
  t.string :name
  t.timestamps
end

and I want to create a migration to change it to this (following the UUID guide here):

create_table :users, id: false do |t|
  t.primary_key :id, :uuid, :default => 'uuid_generate_v1()'
  t.string :name
  t.timestamps
end

I can add/drop/change columns, but I can't figure out how to put the id: false into the table. So far the only way I've come up with is to completely nuke the table via drop_table :users and then re-create it, which seems mighty inefficient to me. Is there some ActiveRecord method I can invoke to add an options hash? Tried to google it with no success, but maybe I don't know what the right search query is?

Any help would be appreciated. Thanks in advance!

Edited: grammar.

Upvotes: 3

Views: 2841

Answers (1)

xph
xph

Reputation: 752

Fixed! Discovered that passing in id: false simply means the id column is not generated in the database, so calling remove_column :users, :id would drop the column and add id: false to the schema.

Key insight came from the following older thread: Add Id column in a migration

For completeness, the full migration file:

def up
  remove_column :users, :id
  add_column :users, :id, :uuid, default: 'uuid_generate_v1()'
end
def down
  remove_column :users, :id
  add_column :users, :id, :primary_key
end

Upvotes: 5

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