Rails 3:在Postgres支持的ActiveRecord中使用json作为列类型时出现迁移错误

Question

我正在运行Rails 3.2.17和Postgres 9.3.4.我使用"rails generate"创建了一个新的ActiveRecord模型,其中一个列类型是json.我的目的是在Postgres中使用json列类型.

db迁移包含以下代码:

class CreateThing < ActiveRecord::Migration
  def change
    create_table :things do |t|
      t.integer :user_id
      t.json :json_data
      t.timestamps
    end
    add_index :things, :user_id
  end
end

当我尝试使用"rake db:migrate"进行迁移时出现此错误:

-- create_table(:things)
rake aborted!
StandardError: An error has occurred, this and all later migrations canceled:

undefined method `json' for #<ActiveRecord::ConnectionAdapters::PostgreSQLAdapter::TableDefinition:0x007fea3d465af8>/Users/../db/migrate/20140425030855_create_things.rb:7:in `block in change'
/Library/Ruby/Gems/2.0.0/gems/activerecord-3.2.17/lib/active_record/connection_adapters/abstract/schema_statements.rb:160:in `create_table'

这是将json列添加到ActiveRecord的正确方法吗？我找不到任何文档或示例.谢谢!

Answer 1

改变您的迁移

class CreateThing < ActiveRecord::Migration
  def change
    create_table :things do |t|
      t.integer :user_id
      t.column :json_data, :json   # Edited
      t.timestamps
    end
    add_index :things, :user_id
  end
end

默认情况下,rake db任务将查看schema.rb(对于postgres不会是这种情况)所以在application.rb中将其更改为

config.active_record.schema_format = :sql