您如何在Rails中创建一系列电子邮件？

Question

I am trying to create an array of emails from my user model, with a helper method to access them. I will then load this array into a drop down selector. I am new to rails, and the MVC framework is new to me also.

In my application_helper.rb

  def create_user_selector_array
    @user = User.select(:email).distinct
  end

In my _form.html.erb partial

<%= f.select(:associate, @user.map { |value| [ value, value ] }) %>
<%= @user %> 

What appears to be happing when I launch this site, is that my selector contains this:

#<User:>(Characters)

And when I pull just the array it prints this:

ActiveRecord::Relation::ActiveRecord_Relation_User:0x007fb28894d508>

I feel close, but I'm not entirely sure what I'm doing wrong here.

Answer 1

In Rails 3.2 and newer, you can use pluck :

User.pluck(:email)
# => ["foo@example.com", "bar@example.com"]

Otherwise, your solution just needed a map :

@user = User.select(:email).distinct.map(&:email)

Using select just determines what fields get returned, however you still get an array of ActiveRecord objects, not strings like you were expecting.