I'm creating a form\_for in which one of the field fetches the drop-down list from the database. I'm interpolating the data to display the string but I want to store its id back into other database which is linked with my form.

---

```
class FlightsController < ApplicationController
  def new
    @flight = Flight.new
    @airplane = @flight.airplane
    @options = Airport.list
  end

  def create
    @flight = Flight.new(flight_params)
    if @flight.save!
      flash[:success] = "Flight created successfully."
      redirect_to @flight
    else
      flash[:danger] = "Flight not created."
      redirect_to :new
    end
  end

  private

    def flight_params
      params.require(:flight).permit(:name, :origin, :destination, :depart, :arrive, :fare, :airplane_id)
    end
end

```

---

```
<%= form_for(@flight) do |f| %>
  ...
  <div class="row">
    <div class="form-group col-md-6">
      <%= f.label :origin %>
      <%= f.select :origin, grouped_options_for_select(@options), { include_blank: "Any", class: "form-control selectpicker", data: { "live-search": true } } %>
    </div>
  </div>
...
<% end %>

```

---

```
class Airport < ApplicationRecord
  def self.list
    grouped_list = {}
    includes(:country).order("countries.name", :name).each do |a|
      grouped_list[a.country.name] ||= [["#{a.country.iso} #{a.country.name}", a.country.iso]]
      grouped_list[a.country.name] << ["#{a.iata} #{a.name} (#{a.city}, #{a.country.name})", a.id]
    end
    grouped_list
  end
end

```

---

```
class Flight < ApplicationRecord
  belongs_to :origin, class_name: "Airport"
  belongs_to :destination, class_name: "Airport"
  belongs_to :airplane
  has_many :bookings, dependent: :destroy
  has_many :passengers, through: :bookings
end

```

---

The following error is showing,

> 
> `Airport(#69813853361360) expected, got "43" which is an instance of String(#47256130076180)`
> 
> 
> 

---

The output of `Airport.list` when run in a console is shown below:

```
=> {"India"=>[["IN India", "IN"], ["AGX Agatti Airport (Agatti, India)", 3], ["IXV Along Airport (Along, India)", 5], ["AML Aranmula International Airport (Aranmula, India)", 6], ["IXB Bagdogra International Airport (Siliguri, India)", 50]]}

```

---

```
Parameters: {"utf8"=>"✓", "authenticity_token"=>"+Z8+rkrJkkgaTznnwyTd/QjEoq3kR4ZmoUTp+EpM+320fNFg5rJm+Izx1zBODo/H7IIm3D+yg3ysnVUPmy7ZwQ==", "flight"=>{"name"=>"Indigo", "origin"=>"49", "destination"=>"11", "depart"=>"2019-02-21T21:30", "arrive"=>"2019-02-22T01:30", "fare"=>"2500", "airplane_id"=>"3"}, "commit"=>"Create Flight"}

```

---

I tried using `to_i` but it didn't work.