ruby-on-rails - Rails 4. 将表 id 迁移到 UUID

Question

我有一张 table :
db/migrate/20140731201801_create_voc_brands.rb:

class CreateVocBrands < ActiveRecord::Migration
  def change
    create_table :voc_brands do |t|
      t.string :name

      t.timestamps
    end
  end
end

但是我需要将表更改为此(如果我从零创建它):

class CreateVocBrands < ActiveRecord::Migration
  def change
    create_table :voc_brands, :id => false do |t|
      t.uuid :id, :primary_key => true
      t.string :name

      t.timestamps
    end
    add_index :voc_brands, :id
  end
end

如何使用迁移更改此设置？

Answer 1

我和你有同样的问题。要从默认 id 迁移到使用 uuid，我认为您可以使用类似于我所拥有的内容:

class ChangeVocBrandsPrimaryKey < ActiveRecord::Migration
  def change
    add_column :voc_brands, :uuid, :uuid, default: "uuid_generate_v4()", null: false

    change_table :voc_brands do |t|
      t.remove :id
      t.rename :uuid, :id
    end
    execute "ALTER TABLE voc_brands ADD PRIMARY KEY (id);"
  end
end