Rename board_filter_labels table and simplify migration

db/migrate/20170926203418_create_board_filter_labels.rb

-class CreateBoardFilterLabels < ActiveRecord::Migration
-  include Gitlab::Database::MigrationHelpers
-
-  DOWNTIME = false
-
-  disable_ddl_transaction!
-
-  def up
-    create_table :board_filter_labels do |t|
-      t.integer :board_id, null: false, index: true
-      t.integer :label_id, null: false, index: true
-    end
-
-    add_index :board_filter_labels, [:board_id, :label_id], unique: true
-
-    add_concurrent_foreign_key :board_filter_labels, :boards, column: :board_id, on_delete: :cascade
-    add_concurrent_foreign_key :board_filter_labels, :labels, column: :label_id, on_delete: :cascade
-  end
-
-  def down
-    drop_table :board_filter_labels
-  end
-end

db/migrate/20170926203418_create_board_labels.rb

+class CreateBoardLabels < ActiveRecord::Migration
+  DOWNTIME = false
+
+  disable_ddl_transaction!
+
+  def change
+    create_table :board_labels do |t|
+      t.references :board, index: true, foreign_key: { on_delete: :cascade }, null: false
+      t.references :label, index: true, foreign_key: { on_delete: :cascade }, null: false
+      t.index [:board_id, :label_id], unique: true
+    end
+  end
+end

db/schema.rb

@@ -214,14 +214,14 @@ ActiveRecord::Schema.define(version: 20170926203418) do
   add_index "award_emoji", ["awardable_type", "awardable_id"], name: "index_award_emoji_on_awardable_type_and_awardable_id", using: :btree
   add_index "award_emoji", ["user_id", "name"], name: "index_award_emoji_on_user_id_and_name", using: :btree
 
-  create_table "board_filter_labels", force: :cascade do |t|
+  create_table "board_labels", force: :cascade do |t|
     t.integer "board_id", null: false
     t.integer "label_id", null: false
   end
 
-  add_index "board_filter_labels", ["board_id", "label_id"], name: "index_board_filter_labels_on_board_id_and_label_id", unique: true, using: :btree
-  add_index "board_filter_labels", ["board_id"], name: "index_board_filter_labels_on_board_id", using: :btree
-  add_index "board_filter_labels", ["label_id"], name: "index_board_filter_labels_on_label_id", using: :btree
+  add_index "board_labels", ["board_id", "label_id"], name: "index_board_labels_on_board_id_and_label_id", unique: true, using: :btree
+  add_index "board_labels", ["board_id"], name: "index_board_labels_on_board_id", using: :btree
+  add_index "board_labels", ["label_id"], name: "index_board_labels_on_label_id", using: :btree
 
   create_table "boards", force: :cascade do |t|
     t.integer "project_id"
@@ -2059,8 +2059,8 @@ ActiveRecord::Schema.define(version: 20170926203418) do
 
   add_foreign_key "approvals", "merge_requests", name: "fk_310d714958", on_delete: :cascade
   add_foreign_key "approver_groups", "namespaces", column: "group_id", on_delete: :cascade
-  add_foreign_key "board_filter_labels", "boards", name: "fk_53e44f3a07", on_delete: :cascade
-  add_foreign_key "board_filter_labels", "labels", name: "fk_91e18fdcee", on_delete: :cascade
+  add_foreign_key "board_labels", "boards", on_delete: :cascade
+  add_foreign_key "board_labels", "labels", on_delete: :cascade
   add_foreign_key "boards", "namespaces", column: "group_id", name: "fk_1e9a074a35", on_delete: :cascade
   add_foreign_key "boards", "projects", name: "fk_f15266b5f9", on_delete: :cascade
   add_foreign_key "boards", "users", column: "assignee_id", name: "fk_2a3450e77c", on_delete: :nullify