Ruby on rails “接收”；不兼容的字符编码：ASCII-8BIT和UTF-8“；简单Rails迁移时出错

当我运行

rakedb:migrate

时，我有一个小的Rails迁移失败了。这是在使用SQLite3的开发环境中实现的。这就是迁移：

class RemoveMobileUserIdFromDevices < ActiveRecord::Migration
  def up
    remove_column :devices, :mobile_user_id
  end

  def down
    add_column :devices, :mobile_user_id, :integer
  end
end

---

我不确定问题出在哪里，因为我以前的迁移使用了类似的命令，这些命令执行时没有问题。到目前为止，我已经尝试在TextMate中手动键入迁移文件（假定实际文件可能有错误的字符编码）。我还删除了迁移，并通过rails g migration RemoveMobileUsers从设备mobile\u user\u id:integer重新创建了它，但没有看到任何更改。

您的

设备表中还有什么？堆栈跟踪中的“复制表内容中的块”可疑。相当多。。。包括一些我怀疑是导致问题的二进制列。我删除了所有的表条目，然后才能够完成迁移。你知道为什么二进制列会导致这个问题吗？二进制就是二进制，对吗？我认为字符编码与此完全不同。只有在操作二进制数据时，它才会在实际的rails应用程序中发挥作用。
t.binary
可能最终成为一个带有SQLite的纯字符串。SQLite显然使用blob数据类型作为rails二进制列。除了SQLite可能没有真正的二进制支持（）的提示之外，找不到更多信息。经验教训：使用SQLite和Rails迁移的二进制数据可能很棘手。我认为真正的问题是SQLite对模式更改的支持非常有限，因此您最终不得不复制表。再加上Rails不想在直接SQL中进行复制，这可能就是问题所在。
** Invoke db:migrate (first_time)
** Invoke environment (first_time)
** Execute environment
** Invoke db:load_config (first_time)
** Invoke rails_env (first_time)
** Execute rails_env
** Execute db:load_config
** Execute db:migrate
==  RemoveMobileUserIdFromDevices: migrating ==================================
-- remove_column(:devices, :mobile_user_id)
rake aborted!
An error has occurred, this and all later migrations canceled:

incompatible character encodings: ASCII-8BIT and UTF-8
/Users/username/.rvm/gems/ruby-1.9.3-p0/gems/activerecord-3.1.3/lib/active_record/connection_adapters/sqlite_adapter.rb:516:in `*'
/Users/username/.rvm/gems/ruby-1.9.3-p0/gems/activerecord-3.1.3/lib/active_record/connection_adapters/sqlite_adapter.rb:516:in `block in copy_table_contents'
/Users/username/.rvm/gems/ruby-1.9.3-p0/gems/activerecord-3.1.3/lib/active_record/result.rb:20:in `block in each'
/Users/username/.rvm/gems/ruby-1.9.3-p0/gems/activerecord-3.1.3/lib/active_record/result.rb:20:in `each'
/Users/username/.rvm/gems/ruby-1.9.3-p0/gems/activerecord-3.1.3/lib/active_record/result.rb:20:in `each'
/Users/username/.rvm/gems/ruby-1.9.3-p0/gems/activerecord-3.1.3/lib/active_record/connection_adapters/sqlite_adapter.rb:514:in `copy_table_contents'
/Users/username/.rvm/gems/ruby-1.9.3-p0/gems/activerecord-3.1.3/lib/active_record/connection_adapters/sqlite_adapter.rb:478:in `copy_table'
/Users/username/.rvm/gems/ruby-1.9.3-p0/gems/activerecord-3.1.3/lib/active_record/connection_adapters/sqlite_adapter.rb:455:in `move_table'
/Users/username/.rvm/gems/ruby-1.9.3-p0/gems/activerecord-3.1.3/lib/active_record/connection_adapters/sqlite_adapter.rb:448:in `block in alter_table'
/Users/username/.rvm/gems/ruby-1.9.3-p0/gems/activerecord-3.1.3/lib/active_record/connection_adapters/abstract/database_statements.rb:192:in `transaction'
/Users/username/.rvm/gems/ruby-1.9.3-p0/gems/activerecord-3.1.3/lib/active_record/connection_adapters/sqlite_adapter.rb:447:in `alter_table'
/Users/username/.rvm/gems/ruby-1.9.3-p0/gems/activerecord-3.1.3/lib/active_record/connection_adapters/sqlite_adapter.rb:387:in `block in remove_column'
/Users/username/.rvm/gems/ruby-1.9.3-p0/gems/activerecord-3.1.3/lib/active_record/connection_adapters/sqlite_adapter.rb:386:in `each'
/Users/username/.rvm/gems/ruby-1.9.3-p0/gems/activerecord-3.1.3/lib/active_record/connection_adapters/sqlite_adapter.rb:386:in `remove_column'
/Users/username/.rvm/gems/ruby-1.9.3-p0/gems/activerecord-3.1.3/lib/active_record/migration.rb:447:in `block in method_missing'
/Users/username/.rvm/gems/ruby-1.9.3-p0/gems/activerecord-3.1.3/lib/active_record/migration.rb:422:in `block in say_with_time'
/Users/username/.rvm/rubies/ruby-1.9.3-p0/lib/ruby/1.9.1/benchmark.rb:280:in `measure'
/Users/username/.rvm/gems/ruby-1.9.3-p0/gems/activerecord-3.1.3/lib/active_record/migration.rb:422:in `say_with_time'
/Users/username/.rvm/gems/ruby-1.9.3-p0/gems/activerecord-3.1.3/lib/active_record/migration.rb:442:in `method_missing'
/Users/username/[removed]/[removed]/db/migrate/20120127204256_remove_mobile_user_id_from_devices.rb:3:in `up'
/Users/username/.rvm/gems/ruby-1.9.3-p0/gems/activerecord-3.1.3/lib/active_record/migration.rb:394:in `block (2 levels) in migrate'
/Users/username/.rvm/rubies/ruby-1.9.3-p0/lib/ruby/1.9.1/benchmark.rb:280:in `measure'
/Users/username/.rvm/gems/ruby-1.9.3-p0/gems/activerecord-3.1.3/lib/active_record/migration.rb:394:in `block in migrate'
/Users/username/.rvm/gems/ruby-1.9.3-p0/gems/activerecord-3.1.3/lib/active_record/connection_adapters/abstract/connection_pool.rb:185:in `with_connection'
/Users/username/.rvm/gems/ruby-1.9.3-p0/gems/activerecord-3.1.3/lib/active_record/migration.rb:375:in `migrate'
/Users/username/.rvm/gems/ruby-1.9.3-p0/gems/activerecord-3.1.3/lib/active_record/migration.rb:507:in `migrate'
/Users/username/.rvm/gems/ruby-1.9.3-p0/gems/activerecord-3.1.3/lib/active_record/migration.rb:687:in `block (2 levels) in migrate'
/Users/username/.rvm/gems/ruby-1.9.3-p0/gems/activerecord-3.1.3/lib/active_record/migration.rb:742:in `call'
/Users/username/.rvm/gems/ruby-1.9.3-p0/gems/activerecord-3.1.3/lib/active_record/migration.rb:742:in `block in ddl_transaction'
/Users/username/.rvm/gems/ruby-1.9.3-p0/gems/activerecord-3.1.3/lib/active_record/connection_adapters/abstract/database_statements.rb:192:in `transaction'
/Users/username/.rvm/gems/ruby-1.9.3-p0/gems/activerecord-3.1.3/lib/active_record/transactions.rb:208:in `transaction'
/Users/username/.rvm/gems/ruby-1.9.3-p0/gems/activerecord-3.1.3/lib/active_record/migration.rb:742:in `ddl_transaction'
/Users/username/.rvm/gems/ruby-1.9.3-p0/gems/activerecord-3.1.3/lib/active_record/migration.rb:686:in `block in migrate'
/Users/username/.rvm/gems/ruby-1.9.3-p0/gems/activerecord-3.1.3/lib/active_record/migration.rb:671:in `each'
/Users/username/.rvm/gems/ruby-1.9.3-p0/gems/activerecord-3.1.3/lib/active_record/migration.rb:671:in `migrate'
/Users/username/.rvm/gems/ruby-1.9.3-p0/gems/activerecord-3.1.3/lib/active_record/migration.rb:549:in `up'
/Users/username/.rvm/gems/ruby-1.9.3-p0/gems/activerecord-3.1.3/lib/active_record/migration.rb:530:in `migrate'
/Users/username/.rvm/gems/ruby-1.9.3-p0/gems/activerecord-3.1.3/lib/active_record/railties/databases.rake:161:in `block (2 levels) in <top (required)>'
/Users/username/.rvm/gems/ruby-1.9.3-p0/gems/rake-0.9.2.2/lib/rake/task.rb:205:in `call'
/Users/username/.rvm/gems/ruby-1.9.3-p0/gems/rake-0.9.2.2/lib/rake/task.rb:205:in `block in execute'
/Users/username/.rvm/gems/ruby-1.9.3-p0/gems/rake-0.9.2.2/lib/rake/task.rb:200:in `each'
/Users/username/.rvm/gems/ruby-1.9.3-p0/gems/rake-0.9.2.2/lib/rake/task.rb:200:in `execute'
/Users/username/.rvm/gems/ruby-1.9.3-p0/gems/rake-0.9.2.2/lib/rake/task.rb:158:in `block in invoke_with_call_chain'
/Users/username/.rvm/rubies/ruby-1.9.3-p0/lib/ruby/1.9.1/monitor.rb:211:in `mon_synchronize'
/Users/username/.rvm/gems/ruby-1.9.3-p0/gems/rake-0.9.2.2/lib/rake/task.rb:151:in `invoke_with_call_chain'
/Users/username/.rvm/gems/ruby-1.9.3-p0/gems/rake-0.9.2.2/lib/rake/task.rb:144:in `invoke'
/Users/username/.rvm/gems/ruby-1.9.3-p0/gems/rake-0.9.2.2/lib/rake/application.rb:116:in `invoke_task'
/Users/username/.rvm/gems/ruby-1.9.3-p0/gems/rake-0.9.2.2/lib/rake/application.rb:94:in `block (2 levels) in top_level'
/Users/username/.rvm/gems/ruby-1.9.3-p0/gems/rake-0.9.2.2/lib/rake/application.rb:94:in `each'
/Users/username/.rvm/gems/ruby-1.9.3-p0/gems/rake-0.9.2.2/lib/rake/application.rb:94:in `block in top_level'
/Users/username/.rvm/gems/ruby-1.9.3-p0/gems/rake-0.9.2.2/lib/rake/application.rb:133:in `standard_exception_handling'
/Users/username/.rvm/gems/ruby-1.9.3-p0/gems/rake-0.9.2.2/lib/rake/application.rb:88:in `top_level'
/Users/username/.rvm/gems/ruby-1.9.3-p0/gems/rake-0.9.2.2/lib/rake/application.rb:66:in `block in run'
/Users/username/.rvm/gems/ruby-1.9.3-p0/gems/rake-0.9.2.2/lib/rake/application.rb:133:in `standard_exception_handling'
/Users/username/.rvm/gems/ruby-1.9.3-p0/gems/rake-0.9.2.2/lib/rake/application.rb:63:in `run'
/Users/username/.rvm/gems/ruby-1.9.3-p0/gems/rake-0.9.2.2/bin/rake:33:in `<top (required)>'
/Users/username/.rvm/gems/ruby-1.9.3-p0/bin/rake:19:in `load'
/Users/username/.rvm/gems/ruby-1.9.3-p0/bin/rake:19:in `<main>'
Tasks: TOP => db:migrate