ruby-on-rails - Rails 迁移创建带有基于字符串的主键的表

Question

通过主键是字符串而不是 int 的迁移在 Rails 中创建表的正确方法是什么？

我已经尝试按照@oldergod 在下面的答案中建议的那样设置 primary_key 但 baz 似乎仍然设置为 int:

class CreateFoos < ActiveRecord::Migration
  def change
    create_table :foos, primary_key: 'baz' do |t|
    end
  end
end

更新

我试过了

class CreateFoos < ActiveRecord::Migration
  def change
    create_table :foos, primary_key: false do |t|
      t.string :baz
    end
  end
end

这让我更接近了一点，但仍然缺少列上的 PRIMARY 索引。我试过 add_index :foos, :baz, type: :primary 但这会产生以下错误:

SQLite3::SQLException: near "primary": syntax error: CREATE primary INDEX "index_foos_on_baz" ON "foos" ("baz")/Users/kyledecot/.rvm/gems/ruby-1.9.3-p392/gems/sqlite3-1.3.8/lib/sqlite3/database.rb:91:in `initialize'

在查看 http://api.rubyonrails.org/classes/ActiveRecord/ConnectionAdapters/SchemaStatements.html#method-i-add_index_options 之后，这似乎应该可行

Answer 1

如果是字符串有什么不同？查看create table文档。

create_table :foos, primary_key: 'baz' do |t|
  t.column :baz, :string
end

Also note that this just sets the primary key in the table. You additionally need to configure the primary key in the model via self.primary_key=. Models do NOT auto-detect the primary key from their table definition.