How to get an array with column names of a table

Question

I need an array with the column names of a table

Any ideas how I can do this with rails 3.0.0rc?

Answer 1

For ActiveRecord:

Model.column_names

---

For Mongoid:

Model.attribute_names

---

Output:

=> ["id", "title", "body", "created_at", "updated_at"] 

Note: It'll be _id instead of id for Mongoid

Answer 2

Suppose you have a Post model:

Post.column_names
# or
Post.columns.map { |column| column.name }

It will return an array with column names of the table 'posts'.

Answer 3

ActiveRecord::Base#column_names

create a model:

$ rails g model Post title:string body:string

verify app/models/post.rb

class Post < ActiveRecord::Base
end

from your terminal:

$ rake db:migrate
$ rails c
> Post.column_names

should produce:

=> ["id", "title", "body", "created_at", "updated_at"] 

credit to @dombesz's comment in Andrea Pavoni's answer