Ruby-on-rails 尝试更新数据库值时，rails update_attributes 返回 false
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rails update_attributes returns false when trying to update db values
提问by steve
hoping someone here can point me in the right direction.
希望这里有人能指出我正确的方向。
I have a controller Update def running "update_attributes". Currently it returns false, with no error message. I'm fairly new to Ruby, but not to coding, and this has had me stumped for a good few days! I am trying to get the User model and db updated with the values specified below.
我有一个运行“update_attributes”的控制器更新定义。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，这让我难住了好几天！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
my edit def....
我的编辑定义....
def edit
@user = current_user
end
The form sends the following to this update method:
该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: [email protected]
commit: Update
action: update
controller: users
id: '20'
And params[:user] returns:
params[:user] 返回：
{"first_name"=>"Amanda", "last_name"=>"Ross", "is_owner"=>"1", "email"=>"[email protected]"}
All these fields are in attr_accessible in the Model, and I can create a user without any problem.
所有这些字段都在模型中的 attr_accessible 中，我可以毫无问题地创建用户。
here's development.log output (sorry it's a bit messy)....
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"=>"[email protected]"}, "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"=>"[email protected]"}
[1m[35m (0.0ms)[0m begin transaction
[1m[36mUser Exists (0.0ms)[0m [1mSELECT 1 FROM "users" WHERE (LOWER("users"."email") = LOWER('[email protected]') AND "users"."id" != 20) LIMIT 1[0m
[1m[35mUser Exists (0.0ms)[0m SELECT 1 FROM "users" WHERE ("users"."email" = '[email protected]' 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)
Could anyone possibly help point out where I'm going wrong, please?
谁能帮忙指出我哪里出错了，好吗？
Thanks in advance!
提前致谢！
回答by yfeldblum
Both #update_attributesand #savewill first check if your model instance is #valid?before continuing on to write to the database. If your model instance is not #valid?, then these methods will return false. To see what's wrong with your model instance, take a look at your model's #errors.
双方#update_attributes并#save会先检查你的模型实例是#valid?继续到写入到数据库之前。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)
Or, embedded in your method,
或者，嵌入到您的方法中，
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
回答by Galen
You can also get better introspection when updating attributes by calling update_attributes!instead, which raises exceptions instead of just returning false.
您还可以在通过调用update_attributes!来更新属性时获得更好的内省，这会引发异常而不是仅仅返回 false。
