rake db:test:prepare 由于 PG 错误而出错

Question

我的一些 rSpec 测试失败了，我怀疑这是由于测试数据库没有被清除。当我尝试运行 rake db:test:prepare 时，出现以下错误（我在 Rails 3.2 中）。显然，这看起来像是某种 Postgres 问题，看起来 rake 任务正在尝试删除测试数据库以便重新填充它。生产数据库架构加载正常。

我在 lib/tasks/ 中寻找了 rake 任务，但我一直没能找到它。有人知道发生了什么吗？

osx_user-> rake db:test:prepare
[RailsAdmin] RailsAdmin initialization disabled by default. Pass SKIP_RAILS_ADMIN_INITIALIZER=false if you need it.
rake aborted!
ActiveRecord::StatementInvalid: PG::SyntaxError: ERROR:  zero-length delimited identifier at or near """"
LINE 1: DROP DATABASE IF EXISTS ""
                                ^
: DROP DATABASE IF EXISTS ""
/Users/osx_user/.rvm/gems/ruby-1.9.3-p547/gems/activerecord-3.2.14/lib/active_record/connection_adapters/postgresql_adapter.rb:650:in `async_exec'
/Users/osx_user/.rvm/gems/ruby-1.9.3-p547/gems/activerecord-3.2.14/lib/active_record/connection_adapters/postgresql_adapter.rb:650:in `block in execute'
/Users/osx_user/.rvm/gems/ruby-1.9.3-p547/gems/activerecord-3.2.14/lib/active_record/connection_adapters/abstract_adapter.rb:280:in `block in log'
/Users/osx_user/.rvm/gems/ruby-1.9.3-p547/gems/activesupport-3.2.14/lib/active_support/notifications/instrumenter.rb:20:in `instrument'
/Users/osx_user/.rvm/gems/ruby-1.9.3-p547/gems/activerecord-3.2.14/lib/active_record/connection_adapters/abstract_adapter.rb:275:in `log'
/Users/osx_user/.rvm/gems/ruby-1.9.3-p547/gems/activerecord-3.2.14/lib/active_record/connection_adapters/postgresql_adapter.rb:649:in `execute'
/Users/osx_user/.rvm/gems/ruby-1.9.3-p547/gems/activerecord-3.2.14/lib/active_record/connection_adapters/postgresql_adapter.rb:772:in `drop_database'
/Users/osx_user/.rvm/gems/ruby-1.9.3-p547/gems/activerecord-3.2.14/lib/active_record/railties/databases.rake:623:in `drop_database'
/Users/osx_user/.rvm/gems/ruby-1.9.3-p547/gems/activerecord-3.2.14/lib/active_record/railties/databases.rake:532:in `block (3 levels) in <top (required)>'
/Users/osx_user/.rvm/gems/ruby-1.9.3-p547/gems/activerecord-3.2.14/lib/active_record/railties/databases.rake:559:in `block (3 levels) in <top (required)>'
/Users/osx_user/.rvm/gems/ruby-1.9.3-p547/bin/ruby_executable_hooks:15:in `eval'
/Users/osx_user/.rvm/gems/ruby-1.9.3-p547/bin/ruby_executable_hooks:15:in `<main>'
Tasks: TOP => db:test:load => db:test:purge
(See full trace by running task with --trace)

Answer 1

想通了。我的开发环境的 database.yml 文件是这样设置的：

database: <%= ENV['DATABASE_NAME_TEST'] %>

rake 任务正在寻找一个不存在的环境变量。