diff --git a/db/migrate/20210827164533_add_p_grade_references_to_p_articles.rb b/db/migrate/20210827164533_add_p_grade_references_to_p_articles.rb
new file mode 100644
index 0000000..6185877
--- /dev/null
+++ b/db/migrate/20210827164533_add_p_grade_references_to_p_articles.rb
@@ -0,0 +1,5 @@
+class AddPGradeReferencesToPArticles < ActiveRecord::Migration[6.0]
+  def change
+    add_reference :p_articles, :p_grade, foreign_key: true
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index feae45f..6f8e516 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 2021_08_27_164230) do
+ActiveRecord::Schema.define(version: 2021_08_27_164533) do
 
   create_table "accounting_zones", options: "ENGINE=InnoDB DEFAULT CHARSET=utf8mb4", force: :cascade do |t|
     t.string "name"
@@ -985,6 +985,8 @@ ActiveRecord::Schema.define(version: 2021_08_27_164230) do
     t.bigint "p_product_ref_id"
     t.datetime "created_at", precision: 6, null: false
     t.datetime "updated_at", precision: 6, null: false
+    t.bigint "p_grade_id"
+    t.index ["p_grade_id"], name: "index_p_articles_on_p_grade_id"
     t.index ["p_product_ref_id"], name: "index_p_articles_on_p_product_ref_id"
   end
 
@@ -3112,6 +3114,7 @@ ActiveRecord::Schema.define(version: 2021_08_27_164230) do
   add_foreign_key "p_article_serial_nums", "p_articles"
   add_foreign_key "p_article_serial_nums", "p_serial_num_types"
   add_foreign_key "p_article_serial_nums", "p_serial_num_values"
+  add_foreign_key "p_articles", "p_grades"
   add_foreign_key "p_articles", "p_product_refs"
   add_foreign_key "p_commercial_object_brands", "p_commercial_objectives"
   add_foreign_key "p_commercial_object_brands", "p_commercials"