ruby-on-rails – Mysql2 ::错误：密钥的重复条目 – ActiveRecord :: RecordNotUnique没有捕获错误？

我正在使用rails应用程序,并且经常遇到以下错误：

MysqL2::Error: Duplicate entry '3022093-2000000028003-visited' for key 'unique_user_place_relationship'

虽然我已将问题的根源缩小到以下几行：

begin
  up = UserPlace.new(user_place_params)
  up.skip_logging
  up.save!
rescue ActiveRecord::RecordNotUnique => e
  Rails.logger.warn(e)
end

在我的表中,我有以下索引：

key_name                         seq_in_index    column_name
unique_user_place_relationship   1               user_id
unique_user_place_relationship   2               place_id
unique_user_place_relationship   3               relationship

问题是我的user_place.rb中没有validate_uniqueness_of user_id,place_id和relationship吗？

根据我的理解,ActiveRecord：RecordNotUnique应该捕获此错误,因为事务不满足db级别的索引约束.

解决方法

doc说：

Using this validation method in conjunction with
ActiveRecord::Validations#save does not guarantee the absence of
duplicate record insertions,because uniqueness checks on the application level are inherently prone to race conditions. For example,suppose that two users try to post a Comment at the same time,and a Comment’s title must be unique. At the database-level,the actions performed by these users Could be interleaved in the following manner…