yaml_db不工作当转储数据库

Question

我想我rubyonrails项目从sqlite3的到MySQL转换遵循：

• Convert a Ruby on Rails app from sqlite to MySQL?
• https://github.com/ludicast/yaml_db

下面是一个命令行日志：

plee@sos:~/rubyonrails/blog$ gem install yaml_db 
Successfully installed yaml_db-0.2.3 
1 gem installed 
Installing ri documentation for yaml_db-0.2.3... 
Installing RDoc documentation for yaml_db-0.2.3... 

plee@sos:~/rubyonrails/blog$ gem list | grep yaml_db 
yaml_db (0.2.3) 

plee@sos:~/rubyonrails/blog$ rake db:data:dump 
rake aborted! 
Don't know how to build task 'db:data:dump' 

(See full trace by running task with --trace) 

plee@sos:~/rubyonrails/blog$ rake db:dump 
rake aborted! 
Don't know how to build task 'db:dump' 

(See full trace by running task with --trace) 
plee@sos:~/rubyonrails/blog$ 

和我的操作系统信息：

plee@sos:~/rubyonrails/blog$ uname -a 
Linux sos 2.6.38-15-generic-pae #60-Ubuntu SMP Tue May 22 11:48:17 UTC 2012 i686 i686 i386 GNU/Linux 
plee@sos:~/rubyonrails/blog$ lsb_release -a 
No LSB modules are available. 
Distributor ID: Ubuntu 
Description: Ubuntu 11.04 
Release: 11.04 
Codename: natty 

Answer 1

我终于明白了原因。安装需要两个步骤：

步骤1.安装gemyaml_db：

gem install yaml_db

第2步：将它添加到Gemfile下项目主页总监

gem 'yaml_db'

然后我们可以运行rake db:dump，没有任何问题。