使用Rails 5枚举PG阵列

Question

我正在尝试将Rails的枚举用于PostgreSQL的数组列.

class Post < ActiveRecord::Base
  enum tags: { a: 0, b: 1, c: 2 }, array: true
end

但是上面的代码不起作用

有没有办法在数组列上使用枚举像arrtibute支持array: true？

编辑

我想看到以下测试用例通过,但实际上它失败了.

# frozen_string_literal: true

begin
  require "bundler/inline"
rescue LoadError => e
  $stderr.puts "Bundler version 1.10 or later is required. Please update your Bundler"
  raise e
end

gemfile(true) do
  source "https://rubygems.org"

  git_source(:github) { |repo| "https://github.com/#{repo}.git" }

  # Activate the gem you are reporting the issue against.
  gem "activerecord", "5.1.4"
  gem "pg"
end

require "active_record"
require "minitest/autorun"
require "logger"

# Ensure backward compatibility with Minitest 4
Minitest::Test = MiniTest::Unit::TestCase unless defined?(Minitest::Test)

# This connection will do for database-independent bug reports.
ActiveRecord::Base.establish_connection(adapter: "postgresql", database: "test")
ActiveRecord::Base.logger = Logger.new(STDOUT)

ActiveRecord::Schema.define do
  create_table :products, force: true do |t|
    t.integer :type_delivery, default: [], array: true, limit: 8
  end
end

class Product < ActiveRecord::Base
  enum type_delivery: { a: 1, b: 2, c: 3, d: 5 }, array: true
end

class BugTest < Minitest::Test
  def test_array_enum
    product = Product.create!(type_delivery: %w[a b c])
    assert_equal products.type_delivery, %w[a b c]
  end
end

错误是:

/usr/local/var/rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/activerecord-5.1.4/lib/active_record/enum.rb:172:in `block (2 levels) in enum': undefined method `each_with_index' for true:TrueClass (NoMethodError)
    from /usr/local/var/rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/activerecord-5.1.4/lib/active_record/enum.rb:171:in `module_eval'
    from /usr/local/var/rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/activerecord-5.1.4/lib/active_record/enum.rb:171:in `block in enum'
    from /usr/local/var/rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/activerecord-5.1.4/lib/active_record/enum.rb:154:in `each'
    from /usr/local/var/rbenv/versions/2.3.1/lib/ruby/gems/2.3.0/gems/activerecord-5.1.4/lib/active_record/enum.rb:154:in `enum'
    from guides/bug_report_templates/active_record_gem.rb:38:in `<class:Product>'
    from guides/bug_report_templates/active_record_gem.rb:37:in `<main>'

Answer 1

您可以使用array_enum专门为此用例创建的 gem https://github.com/freeletics/array_enum

Answer 2

Rails 的enumapi 将属性映射到单个整数列。如果您愿意，您可以创建自己的位掩码来支持多个属性（就像通常对用户角色所做的那样）。

我认为您正在寻找的是属性 api，您甚至可以实现自定义 ActiveRecord::Type 来处理验证。