Ruby Rails 3.0.9:ActiveRecord唯一性约束在每次更新时都会失败，不会'；唯一列是否为'；不碰

我有一个侧面模型

class Profile < ActiveRecord::Base
    attr_accessible :user_id, :race_id, :nickname, :first_name, :last_name, :gender, :birth_date, :eighteen,
            :time_zone, :metric_scale, :referral_code, :referrer_id, :tag_line

  # Relationships
  belongs_to  :user
  belongs_to  :race
  belongs_to :referred_by, :class_name => "Profile", :foreign_key => "referral_code"
  has_many :referrals, :class_name => "Profile", :foreign_key => "referrer_id"

  # Validations
  validates :user_id, :race_id, :nickname, :first_name, :last_name, :time_zone, :gender, :presence => true
  validates :referral_code, :nickname, :uniqueness => { :case_sensitive => false }

  # Instance Methods
  def full_name
    first_name + " " + last_name
  end

  # Class Methods
  def self.search(search)
    search_condition = "%" + search + "%"
    find(:all, :conditions => ['nickname LIKE ?', search_condition])
  end

  def self.find_by_referral_code(referrer_code)
    find(:one, :conditions => ['referral_code LIKE ?', referrer_code])
  end

end

类配置文件“配置文件”；：外键=>“引用代码”
有很多：推荐人，：class\u name=>“Profile”，：foreign\u key=>“推荐人\u id”
#验证
验证：user\u id、：race\u id、：昵称、：first\u name、：last\u name、：time\u zone、：gender、：presence=>true
验证：引用\代码，：昵称，：唯一性=>{：区分大小写=>false}
#实例方法
def全名
名+姓+姓
结束
#类方法
def self.search（搜索）
搜索条件=“%”+搜索+“%”
查找（：all，：conditions=>['昵称类似？'，搜索条件]）
结束
定义自我。通过推荐代码查找推荐代码（推荐代码）
查找（：one，：conditions=>['reference\u code LIKE？'，referer\u code]）
结束
结束

无论我更新了哪一列，“referral_code”上的唯一性约束为false，我都无法更新模型，也无法找出原因。从我在线阅读的Rails 3来看，ActiveRecord应该是跟踪脏对象，只生成包含修改列的更新查询，而不生成其他列。因为它应该只对唯一列以外的列执行更新查询，所以验证不应该失败。不幸的是。以下是Rails控制台会话，其中显示：

Loading development environment (Rails 3.0.9)
ruby-1.9.2-p180 :001 > profile = Profile.find(3)
 => #<Profile id: 3, user_id: 3, race_id: 2, nickname: "Premium-User", first_name: "Premium", last_name: "User", gender: "M", birth_date: "1977-01-01", eighteen: true, complete: true, time_zone: "Kuala Lumpur", metric_scale: false, referral_code: "bo", referrer_id: nil, tag_line: "This is what its like.", created_at: "2011-09-21 04:08:00", updated_at: "2011-09-21 04:08:00"> 

ruby-1.9.2-p180 :002 > update = {"tag_line"=>"Changed to this"}
 => {"tag_line"=>"Changed to this"} 

ruby-1.9.2-p180 :003 > profile.update_attributes(update)
 => false 

ruby-1.9.2-p180 :004 > profile.errors
 => {:referral_code=>["has already been taken"]}

加载开发环境（Rails 3.0.9）
ruby-1.9.2-p180:001>profile=profile.find（3）
=> # 
ruby-1.9.2-p180:002>更新={“tag_line”=>“更改为此”}
=>{“标记线”=>“更改为此”}
ruby-1.9.2-p180:003>配置文件。更新属性（更新）
=>错误
ruby-1.9.2-p180:004>profile.errors
=>{:referral_code=>[“已采取”]}

即使直接在非唯一的单个列上执行更新，也会导致唯一性约束失败，并且记录不会被更新，下面是一个控制台会话：

Loading development environment (Rails 3.0.9)
ruby-1.9.2-p180 :001 > profile = Profile.find(3)
 => #<Profile id: 3, user_id: 3, race_id: 2, nickname: "Premium-User", first_name: "Premium", last_name: "User", gender: "M", birth_date: "1977-01-01", eighteen: true, complete: true, time_zone: "Kuala Lumpur", metric_scale: false, referral_code: "bo", referrer_id: nil, tag_line: "This is what its like.", created_at: "2011-09-21 04:08:00", updated_at: "2011-09-21 04:08:00"> 

ruby-1.9.2-p180 :002 > profile.tag_line = "changed to this"
 => "changed to this" 

ruby-1.9.2-p180 :003 > profile.save
 => false 

ruby-1.9.2-p180 :004 > profile.errors
 => {:referral_code=>["has already been taken"]}

Loading development environment (Rails 3.0.9)
ruby-1.9.2-p180 :001 > profile = Profile.find(3)
 => #<Profile id: 3, user_id: 3, race_id: 2, nickname: "Premium-User", first_name: "Premium", last_name: "User", gender: "M", birth_date: "1977-01-01", eighteen: true, complete: true, time_zone: "Kuala Lumpur", metric_scale: false, referral_code: "bo", referrer_id: nil, tag_line: "This is what its like.", created_at: "2011-09-21 04:08:00", updated_at: "2011-09-21 04:08:00"> 

ruby-1.9.2-p180 :002 > profile.tag_line = "change to this"
 => "change to this" 

ruby-1.9.2-p180 :003 > profile.changes
 => {"tag_line"=>["This is what its like.", "change to this"]} 

ruby-1.9.2-p180 :004 > profile.save
 => false 

ruby-1.9.2-p180 :005 > profile.errors
 => {:referral_code=>["has already been taken"]}

加载开发环境（Rails 3.0.9）
ruby-1.9.2-p180:001>profile=profile.find（3）
=> # 
ruby-1.9.2-p180:002>profile.tag\u line=“更改为此”
=>“已更改为此”
ruby-1.9.2-p180:003>profile.save
=>错误
ruby-1.9.2-p180:004>profile.errors
=>{:referral_code=>[“已采取”]}

我还运行了一个检查，查看ActiveRecord是否确实在跟踪脏对象，它似乎是这样的，下面是控制台会话：

Loading development environment (Rails 3.0.9)
ruby-1.9.2-p180 :001 > profile = Profile.find(3)
 => #<Profile id: 3, user_id: 3, race_id: 2, nickname: "Premium-User", first_name: "Premium", last_name: "User", gender: "M", birth_date: "1977-01-01", eighteen: true, complete: true, time_zone: "Kuala Lumpur", metric_scale: false, referral_code: "bo", referrer_id: nil, tag_line: "This is what its like.", created_at: "2011-09-21 04:08:00", updated_at: "2011-09-21 04:08:00"> 

ruby-1.9.2-p180 :002 > profile.tag_line = "changed to this"
 => "changed to this" 

ruby-1.9.2-p180 :003 > profile.save
 => false 

ruby-1.9.2-p180 :004 > profile.errors
 => {:referral_code=>["has already been taken"]}

Loading development environment (Rails 3.0.9)
ruby-1.9.2-p180 :001 > profile = Profile.find(3)
 => #<Profile id: 3, user_id: 3, race_id: 2, nickname: "Premium-User", first_name: "Premium", last_name: "User", gender: "M", birth_date: "1977-01-01", eighteen: true, complete: true, time_zone: "Kuala Lumpur", metric_scale: false, referral_code: "bo", referrer_id: nil, tag_line: "This is what its like.", created_at: "2011-09-21 04:08:00", updated_at: "2011-09-21 04:08:00"> 

ruby-1.9.2-p180 :002 > profile.tag_line = "change to this"
 => "change to this" 

ruby-1.9.2-p180 :003 > profile.changes
 => {"tag_line"=>["This is what its like.", "change to this"]} 

ruby-1.9.2-p180 :004 > profile.save
 => false 

ruby-1.9.2-p180 :005 > profile.errors
 => {:referral_code=>["has already been taken"]}

加载开发环境（Rails 3.0.9）
ruby-1.9.2-p180:001>profile=profile.find（3）
=> # 
ruby-1.9.2-p180:002>profile.tag\u line=“更改为此”
=>“更改为此”
ruby-1.9.2-p180:003>profile.changes
=>{“tag_line”=>[“这就是它的样子。”，“改成这个”]}
ruby-1.9.2-p180:004>profile.save
=>错误
ruby-1.9.2-p180:005>profile.errors
=>{:referral_code=>[“已采取”]}

---

老实说，我真是不知所措，我花了相当多的时间来研究它，也搜索了谷歌，但我找不到一个答案来解释为什么会发生这种情况。

你是对的，Rails只“跟踪”脏列，并生成所需的最小更新语句。如果查看log/development.log文件，您将看到正在生成的实际SQL，并且您将看到update语句只涉及您编辑的列。如果你的代码有那么大的进步，至少你会这么做

在保存模型之前，Rails将在模型上运行所有验证，其中包括查看引用代码是否唯一。为此，它将对要检查的数据库运行SELECTSQL语句；如果查看development.log文件，您肯定会看到此查询

所以Rails在这里工作正常

---

如果你的推荐代码应该是唯一的，为什么不呢？我的猜测是，您试图用零或空代码保存模型。如果是这种情况，请尝试将

：allow\u nil=>true

或

：allow\u blank=>true

添加到：university散列中。

您从概要文件中得到了什么。按引用代码查找所有内容（Profile.reference\u code）？此约束是否也在数据库级别实现？转储该表的DDL并检查是否存在任何键/约束。还要检查log/development.log以获取更新正在运行的实际SQL查询。