新增：项目语言新增唯一性验证

app/controllers/admins/project_languages_controller.rb

@@ -27,17 +27,18 @@ class Admins::ProjectLanguagesController < Admins::BaseController
       flash[:success] = '创建成功'
     else
       redirect_to admins_project_languages_path
-      flash[:danger] = '创建失败'
+      flash[:danger] = @project_language.errors.full_messages.join(",")
     end
   end
 
   def update 
-    if @project_language.update_attribute(:name, @name)
+    @project_language.attributes = {name: @name}
+    if @project_language.save
       redirect_to admins_project_languages_path
       flash[:success] = '更新成功'
     else 
       redirect_to admins_project_languages_path
-      flash[:success] = '更新失败'
+      flash[:danger] = @project_language.errors.full_messages.join(",")
     end
   end
 

app/models/project_language.rb

@@ -12,4 +12,6 @@
 
 class ProjectLanguage < ApplicationRecord
   include Projectable
+
+  validates :name, uniqueness: true
 end