add nested set to treatments

app/models/citation.rb

@@ -78,7 +78,11 @@ class Citation < ApplicationRecord
   end
 
   def self.by_treatment(treatment)
-    includes(:treatments).references(:treatments).where('treatments.id = ?', treatment)
+    # get the citations with the treatment and all of the child treatments
+    trt = Treatment.find(treatment)
+    child_ids = trt.children.map { |sib| sib.id }
+    ids = child_ids.push(trt.id)
+    includes(:treatments).references(:treatments).where('treatments.id in (?)', ids)
   end
 
   def self.by_treatments(treatment_array)

db/migrate/20240618131120_add_awesome_nested_set_to_treatments.rb

@@ -0,0 +1,7 @@
+class AddAwesomeNestedSetToTreatments < ActiveRecord::Migration[7.1]
+  def change
+    add_column :treatments, :parent_id, :integer, null: true
+    add_column :treatments, :rgt, :integer
+    add_column :treatments, :lft, :integer
+  end
+end