ruby-on-rails - 尝试更新数据库值时，rails update_attributes 返回 false

Question

希望这里有人能给我指出正确的方向。

我有一个 Controller Update def 运行“update_attributes”。目前它返回 false，没有错误消息。我是 Ruby 的新手，但不是编码的新手，这让我困惑了好几天!我正在尝试使用下面指定的值更新用户模型和数据库。

def update   
    #get currently logged in user
    @user = current_user
    #update user params based on edit form...
    if @user.update_attributes(params[:user])
        redirect_to profile_path, :notice  => "Successfully updated profile."
    else
        render :action => 'edit'
    end
end

我的编辑定义....

def edit
    @user = current_user
end

表单将以下内容发送到此更新方法:

--- !ruby/hash:ActiveSupport::HashWithIndifferentAccess
utf8: ✓
_method: put
authenticity_token: 9T4ihVI0p8j7pZEFxof3Bfahi2a+o3BPmtXJDnfHT4o=
user: !ruby/hash:ActiveSupport::HashWithIndifferentAccess
  first_name: Amanda
  last_name: Ross
  is_owner: '1'
  email: example@googlemail.com
commit: Update
action: update
controller: users
id: '20'

params[:user] 返回:

{"first_name"=>"Amanda", "last_name"=>"Ross", "is_owner"=>"1", "email"=>"example@googlemail.com"}

所有这些字段都在模型的 attr_accessible 中，我可以毫无问题地创建一个用户。

这是 development.log 输出(抱歉有点乱)...

Started PUT "/users/20" for 127.0.0.1 at 2012-04-17 10:39:29 +0100
Processing by UsersController#update as HTML
  Parameters: {"utf8"=>"✓", "authenticity_token"=>"9T4ihVI0p8j7pZEFxof3Bfahi2a+o3BPmtXJDnfHT4o=", "user"=>    {"first_name"=>"Amanda", "last_name"=>"Ross", "is_owner"=>"1", "email"=>"example@googlemail.com"},     "commit"=>"Update", "id"=>"20"}
  [1m[36mUser Load (1.0ms)[0m  [1mSELECT "users".* FROM "users" WHERE "users"."id" = 20 LIMIT 1[0m
>>>>>>>>>>>>
{"first_name"=>"Amanda", "last_name"=>"Ross", "is_owner"=>"1", "email"=>"example@googlemail.com"}
     [1m[35m (0.0ms)[0m  begin transaction
     [1m[36mUser Exists (0.0ms)[0m  [1mSELECT 1 FROM "users" WHERE (LOWER("users"."email") =     LOWER('example@googlemail.com') AND "users"."id" != 20) LIMIT 1[0m
  [1m[35mUser Exists (0.0ms)[0m  SELECT 1 FROM "users" WHERE ("users"."email" = 'example@googlemail.com'     AND "users"."id" != 20) LIMIT 1
  [1m[36m (0.0ms)[0m  [1mrollback transaction[0m
 Rendered users/_form.html.erb (7.0ms)
 Rendered users/edit.html.erb within layouts/application (10.0ms)
 Rendered layouts/_includes.html.erb (30.0ms)

谁能帮我指出我哪里出错了，好吗？

提前致谢!

Answer 1

#update_attributes 和#save 将首先检查您的模型实例是否为#valid?，然后再继续写入数据库。如果您的模型实例不是 #valid?，那么这些方法将返回 false。要查看模型实例有什么问题，请查看模型的 #errors。

Rails.logger.info(@user.errors.messages.inspect)

或者，嵌入到你的方法中，

def update   
  @user = current_user
  if @user.update_attributes(params[:user])
    redirect_to profile_path, :notice  => "Successfully updated profile."
  else
    # print the errors to the development log
    Rails.logger.info(@user.errors.messages.inspect)
    render :action => 'edit'
  end
end