如何在Rails中的ActiveRecord中获取对象的所有值？

Question

可以使用column_names来获取表的所有列，但是如果想知道 ActiveRecord 中特定实例的所有值怎么办。

例如，

User.column_names
=> ["id", "email", "encrypted_password", "reset_password_token", "reset_password_sent_at", "remember_created_at", "sign_in_count", "current_sign_in_at", "last_sign_in_at", "current_sign_in_ip", "last_sign_in_ip", "tel", "interests", "admin_status", "created_at", "updated_at", "city_id", "profile_image_file_name", "profile_image_content_type", "profile_image_file_size", "profile_image_updated_at"]

User.first
=> #<User id: 1, email: "aatir@jpl.com", tel: "+923223333333", interests: "Hi, I'm interested in coding.", admin_status: "download", created_at: "2016-08-16 22:38:05", updated_at: "2016-08-16 22:38:05", city_id: 2, profile_image_file_name: "Screen_Shot_2016-07-02_at_4.41.32_PM.png", profile_image_content_type: "image/png", profile_image_file_size: 324372, profile_image_updated_at: "2016-08-16 22:38:04">

当first方法被调用时，它返回键值对。 我想要的是只有值，ActiveRecord 中是否有一个方法可以为我们做到这一点？

Answer 1

您也可以使用attributes方法来获取它

User.first.attributes.values

1. User.first.attributes将返回user对象的哈希表示

   User.first.attributes { "id" => 1, "email" => "aatir@jpl.com", "tel" => "+923223333333", "interests" => "Hi, I'm interested in coding.", "admin_status" => "download", "created_at" => "2016-08-16 22:38:05", "updated_at" => "2016-08-16 22:38:05", "city_id" => 2, "profile_image_file_name" => "Screen_Shot_2016-07-02_at_4.41.32_PM.png", "profile_image_content_type" => "image/png", "profile_image_file_size" => 324372, "profile_image_updated_at" => "2016-08-16 22:38:04" }

2. values将返回Array的值

   User.first.attributes.values [1, "aatir@jpl.com", "+923223333333", "Hi, I'm interested in coding.", "download", "2016-08-16 22:38:05", "2016-08-16 22:38:05", 2, "Screen_Shot_2016-07-02_at_4.41.32_PM.png", "image/png", 324372, "2016-08-16 22:38:04"]

Answer 2

我正在扩展@deepak 的答案，以确保顺序与column_names的顺序保持相同，这就是我实现它的方式：

User.first.attributes.values_at *User.column_names

无论顺序如何，只获取值：

User.first.attributes.values 

Answer 3

只是您可以将 activerecord 转换为 Hash 然后获取如下值：

User.first.as_json.values

Answer 4

Object.first.attributes.values