db: add uniqueness constraints to Champs

db/migrate/20210722133440_add_unique_index_to_champs.rb

@@ -0,0 +1,14 @@
+class AddUniqueIndexToChamps < ActiveRecord::Migration[6.1]
+  include Database::MigrationHelpers
+
+  disable_ddl_transaction!
+
+  def up
+    delete_duplicates :champs, [:type_de_champ_id, :dossier_id, :row]
+    add_concurrent_index :champs, [:type_de_champ_id, :dossier_id, :row], unique: true
+  end
+
+  def down
+    remove_index :champs, [:type_de_champ_id, :dossier_id, :row]
+  end
+end

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_06_04_095054) do
+ActiveRecord::Schema.define(version: 2021_07_22_133440) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
@@ -174,6 +174,7 @@ ActiveRecord::Schema.define(version: 2021_06_04_095054) do
     t.index ["parent_id"], name: "index_champs_on_parent_id"
     t.index ["private"], name: "index_champs_on_private"
     t.index ["row"], name: "index_champs_on_row"
+    t.index ["type_de_champ_id", "dossier_id", "row"], name: "index_champs_on_type_de_champ_id_and_dossier_id_and_row", unique: true
     t.index ["type_de_champ_id"], name: "index_champs_on_type_de_champ_id"
   end