I am representing a graph structrure in my DB. I have a table for nodes
(which holds node names for now) and a table for segments/links. Each
segment has the id-s of its 2 end-nodes.
How do i specify this in the Rails model for a Segment ? I can't say
belongs_to twice ...
Is there a better way to do this ?
Something along these lines? This creates a directed graph, you would
just add two segments for each node pair with the source/target
reversed if you want an undirected graph.
class Node < ActiveRecord::Base
has_many :nodes, :through => :segments, :source => :target
class Segment < ActiveRecord::Base
belongs_to :source, :class_name => "Node"
belongs_to :target, :class_name => "Node"
create_table "nodes" do |t|
t.column "name", :string
create_table "segments" do |t|
t.column "source_id", :integer
t.column "target_id", :integer