Enum, default value reseted to nil on save

Question

In a RoR 7.1.3 application using PostgreSQL, I've a enum defined as:

create_enum :foo_states, %i[active inactive]

create_table :foo do |t|
  t.enum :state, enum_type: :foo_states, default: :active, null: false
end

class Foo < ApplicationRecord
  enum :state, %i[active inactive], default: :active, validate: true
end

When I instanciate a new object it works fine:

Foo.new
=> #<Foo state: "active">

Foo.create(state: :bar).errors
=> #<ActiveModel::Errors [#<ActiveModel::Error attribute=state, type=inclusion, ...

But when saving records it does not persist its state:

foo = Foo.new
=> #<Foo state: "active">

foo.save
=> #<Foo state: nil>

# same on .create
Foo.create
=> #<Foo state: nil>

Is this the expected behaviour? If so, how am I using this feature incorrectly?

Answer 1

You create enum in the database layer with active and inactive strings as possible values

But when you write in the model

enum :state, %i[active inactive], default: :active, validate: true

it means you will try to save 0 for active and 1 for inactive (index as integer)

Instead of this define enum in the model as hash such way

enum :state, { active: 'active', inactive: 'inactive' }, default: :active, validate: true

From the docs:

Declare an enum attribute where the values map to integers in the database, but can be queried by name

class Conversation < ActiveRecord::Base
  enum :status, [ :active, :archived ]
end

# conversation.update! status: 0
conversation.active!

Finally it’s also possible to use a string column to persist the enumerated value

class Conversation < ActiveRecord::Base
  enum :status, active: "active", archived: "archived"
end