【问题标题】:Build associations for User favorites' other users为用户收藏的其他用户建立关联
【发布时间】:2011-10-17 10:38:56
【问题描述】:

我想建立一个简单的收藏系统。我在网上找到了多态关联的教程,但我相信还有更简单的!!

所以我有一个用户模型,我想让用户拥有许多其他用户作为收藏夹。 另一方面,用户可能会知道谁喜欢他。

我尝试过这样的事情:

class User < ActiveRecord::Base
  has_many :favorites, :class_name => 'User', :foreign_key => 'user_id'
  belongs_to :favorited_by, :class_name => 'User'
end

但是我在执行时遇到了 SQL 错误

some_user.favorites << another_user

some_user.favorites.build(another_user)
some_user.save
some_user.favorites

任何帮助做这个简单的事情... :)

这是踪迹:

ActiveRecord::StatementInvalid: SQLite3::SQLException: no such column: users.user_id: SELECT "users".* FROM "users" WHERE ("users".user_id = 1)
from /Users/pierrelouisgottfrois/.rvm/gems/ruby-1.9.2-p180/gems/activerecord-3.0.9/lib/active_record/connection_adapters/abstract_adapter.rb:207:in `rescue in log'
from /Users/pierrelouisgottfrois/.rvm/gems/ruby-1.9.2-p180/gems/activerecord-3.0.9/lib/active_record/connection_adapters/abstract_adapter.rb:199:in `log'
from /Users/pierrelouisgottfrois/.rvm/gems/ruby-1.9.2-p180/gems/activerecord-3.0.9/lib/active_record/connection_adapters/sqlite_adapter.rb:135:in `execute'
from /Users/pierrelouisgottfrois/.rvm/gems/ruby-1.9.2-p180/gems/activerecord-3.0.9/lib/active_record/connection_adapters/sqlite_adapter.rb:284:in `select'
from /Users/pierrelouisgottfrois/.rvm/gems/ruby-1.9.2-p180/gems/activerecord-3.0.9/lib/active_record/connection_adapters/abstract/database_statements.rb:7:in `select_all'
from /Users/pierrelouisgottfrois/.rvm/gems/ruby-1.9.2-p180/gems/activerecord-3.0.9/lib/active_record/connection_adapters/abstract/query_cache.rb:56:in `select_all'
from /Users/pierrelouisgottfrois/.rvm/gems/ruby-1.9.2-p180/gems/activerecord-3.0.9/lib/active_record/base.rb:473:in `find_by_sql'
from /Users/pierrelouisgottfrois/.rvm/gems/ruby-1.9.2-p180/gems/activerecord-3.0.9/lib/active_record/relation.rb:64:in `to_a'
from /Users/pierrelouisgottfrois/.rvm/gems/ruby-1.9.2-p180/gems/activerecord-3.0.9/lib/active_record/relation/finder_methods.rb:143:in `all'
from /Users/pierrelouisgottfrois/.rvm/gems/ruby-1.9.2-p180/gems/activerecord-3.0.9/lib/active_record/associations/association_collection.rb:70:in `block in find'
from /Users/pierrelouisgottfrois/.rvm/gems/ruby-1.9.2-p180/gems/activerecord-3.0.9/lib/active_record/base.rb:1127:in `with_scope'
from /Users/pierrelouisgottfrois/.rvm/gems/ruby-1.9.2-p180/gems/activerecord-3.0.9/lib/active_record/associations/association_proxy.rb:207:in `with_scope'
from /Users/pierrelouisgottfrois/.rvm/gems/ruby-1.9.2-p180/gems/activerecord-3.0.9/lib/active_record/associations/association_collection.rb:63:in `find'
from /Users/pierrelouisgottfrois/.rvm/gems/ruby-1.9.2-p180/gems/activerecord-3.0.9/lib/active_record/associations/association_collection.rb:468:in `find_target'
from /Users/pierrelouisgottfrois/.rvm/gems/ruby-1.9.2-p180/gems/activerecord-3.0.9/lib/active_record/associations/association_collection.rb:398:in `load_target'
from /Users/pierrelouisgottfrois/.rvm/gems/ruby-1.9.2-p180/gems/activerecord-3.0.9/lib/active_record/associations/association_proxy.rb:145:in `inspect'
from /Users/pierrelouisgottfrois/.rvm/gems/ruby-1.9.2-p180/gems/railties-3.0.9/lib/rails/commands/console.rb:44:in `start'
from /Users/pierrelouisgottfrois/.rvm/gems/ruby-1.9.2-p180/gems/railties-3.0.9/lib/rails/commands/console.rb:8:in `start'
from /Users/pierrelouisgottfrois/.rvm/gems/ruby-1.9.2-p180/gems/railties-3.0.9/lib/rails/commands.rb:23:in `<top (required)>'
from script/rails:6:in `require'

【问题讨论】:

标签: ruby-on-rails ruby associations


【解决方案1】:

回答我自己对@Dogbert 的感谢

您的模型关联错误。看看我的回答 here 并根据您的用例进行调整。

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