model reference

[tanizawa]

hi

I am tanizawa

I am searching how to add  reference of two same table.

Please teach me how to add .

exmple:

class CreateLocationjs < ActiveRecord::Migration

  def change

    create_table :locationjs do |t|

      t.references :locationm  <----start point

                                         <--- I want to add  end point  field.

[Patrick Mulder]

Not sure what your exact question is, but this example below
references a location 2 times:

# Create models:
rails g model location name:string
rails g model route

# Add associations between models:
in Location, add:
has_many :routes

in Route, add:
belongs_to :location_start, :class_name => Location, :foreign_key
=> "location_start_id"
belongs_to :location_end, :class_name => Location, :foreign_key
=> "location_end_id"

# Define foreign keys in db migration:

class CreateRoutes < ActiveRecord::Migration
def change
create_table :routes do |t|
t.references :location_start
t.references :location_end

t.timestamps
end
end
end

# Now in console:
munich = Location.new
munich.name = "Munich"; munich.save!

tokyo = Location.new
tokyo.name = "Tokyo"; tokyo.save!

route = Route.new
route.location_start = munich
route.location_end = tokyo
route.save!

[tanizawa kazuya]

Thank you for your code.

I couldn't have done it without you.

I understand how to add some reference for same table.

2012/6/18 Patrick Mulder <mulder....@gmail.com>

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