Ruby Rails 将数据库和数据从 SQLite3 迁移到 Postgres
Ruby on Rails migrate database and data from SQLite3 to Postgres
我正在尝试将一个小型 SQLite 数据库迁移到 PostgreSQL，以便我可以将它放在 Heroku 上。计划是将本地数据库迁移到 PostgreSQL 实例。一旦我知道它工作正常，我就会将数据库迁移到 heroku。
事实证明这是非常困难的。我不习惯在 Rails 上 Ruby，所以可能错过了所有技巧。
我 运行 Ruby 2.2.0 / Rails 4.2.0 MAC
关于问题的任何想法/
我运行下面的命令从SQLite3迁移到PostgreSQL。请注意 Db:migrate 有效并且数据库模式已就位。我现在只需要将数据放入其中。
taps pull postgres://user@localhost/db/development http://user:secret@localhost:5000
然后我得到以下输出：
Receiving schema Unable to fetch tables information from http://user:secret@localhost:5000. Please check the server log.
在我启动服务的另一个终端中，我得到以下内容，其中包含一个引用 table:
的错误
Rack::Utils::OkJson::Error - cannot encode Symbol: :schema_migrations::
$ **taps server sqlite://db/development.sqlite3 USER secret**
== Sinatra/1.0 has taken the stage on 5000 for production with backup from WEBrick
[2015-05-06 17:28:09] INFO WEBrick 1.3.1
[2015-05-06 17:28:09] INFO ruby 2.2.0 (2014-12-25) [x86_64-darwin14]
[2015-05-06 17:28:09] INFO WEBrick::HTTPServer#start: pid=8274 port=5000
127.0.0.1 - USER [06/May/2015:17:28:57 +0100] "GET / HTTP/1.1" 200 - 0.0010
localhost - - [06/May/2015:17:28:57 BST] "GET / HTTP/1.1" 200 31
- -> /
127.0.0.1 - USER [06/May/2015:17:28:57 +0100] "POST /sessions HTTP/1.1" 200 - 0.0158
localhost - - [06/May/2015:17:28:57 BST] "POST /sessions HTTP/1.1" 200 46
- -> /sessions
Rack::Utils::OkJson::Error - cannot encode Symbol: :schema_migrations:
/Users/USER/.rvm/gems/ruby-2.2.0/gems/rack-1.6.0/lib/rack/utils/okjson.rb:427:in `valenc'
/Users/USER/.rvm/gems/ruby-2.2.0/gems/rack-1.6.0/lib/rack/utils/okjson.rb:438:in `block in arrenc'
/Users/USER/.rvm/gems/ruby-2.2.0/gems/rack-1.6.0/lib/rack/utils/okjson.rb:438:in `map'
/Users/USER/.rvm/gems/ruby-2.2.0/gems/rack-1.6.0/lib/rack/utils/okjson.rb:438:in `arrenc'
/Users/USER/.rvm/gems/ruby-2.2.0/gems/rack-1.6.0/lib/rack/utils/okjson.rb:410:in `encode'
/Users/USER/.rvm/gems/ruby-2.2.0/gems/taps-0.3.24/lib/taps/server.rb:157:in `block in <class:Server>'
/Users/USER/.rvm/gems/ruby-2.2.0/gems/sinatra-1.0/lib/sinatra/base.rb:865:in `call'
/Users/USER/.rvm/gems/ruby-2.2.0/gems/sinatra-1.0/lib/sinatra/base.rb:865:in `block in route'
/Users/USER/.rvm/gems/ruby-2.2.0/gems/sinatra-1.0/lib/sinatra/base.rb:521:in `instance_eval'
/Users/USER/.rvm/gems/ruby-2.2.0/gems/sinatra-1.0/lib/sinatra/base.rb:521:in `route_eval'
/Users/USER/.rvm/gems/ruby-2.2.0/gems/sinatra-1.0/lib/sinatra/base.rb:500:in `block (2 levels) in route!'
/Users/USER/.rvm/gems/ruby-2.2.0/gems/sinatra-1.0/lib/sinatra/base.rb:497:in `catch'
/Users/USER/.rvm/gems/ruby-2.2.0/gems/sinatra-1.0/lib/sinatra/base.rb:497:in `block in route!'
/Users/USER/.rvm/gems/ruby-2.2.0/gems/sinatra-1.0/lib/sinatra/base.rb:476:in `each'
/Users/USER/.rvm/gems/ruby-2.2.0/gems/sinatra-1.0/lib/sinatra/base.rb:476:in `route!'
/Users/USER/.rvm/gems/ruby-2.2.0/gems/sinatra-1.0/lib/sinatra/base.rb:601:in `dispatch!'
/Users/USER/.rvm/gems/ruby-2.2.0/gems/sinatra-1.0/lib/sinatra/base.rb:411:in `block in call!'
/Users/USER/.rvm/gems/ruby-2.2.0/gems/sinatra-1.0/lib/sinatra/base.rb:566:in `instance_eval'
/Users/USER/.rvm/gems/ruby-2.2.0/gems/sinatra-1.0/lib/sinatra/base.rb:566:in `block in invoke'
/Users/USER/.rvm/gems/ruby-2.2.0/gems/sinatra-1.0/lib/sinatra/base.rb:566:in `catch'
/Users/USER/.rvm/gems/ruby-2.2.0/gems/sinatra-1.0/lib/sinatra/base.rb:566:in `invoke'
/Users/USER/.rvm/gems/ruby-2.2.0/gems/sinatra-1.0/lib/sinatra/base.rb:411:in `call!'
/Users/USER/.rvm/gems/ruby-2.2.0/gems/sinatra-1.0/lib/sinatra/base.rb:399:in `call'
/Users/USER/.rvm/gems/ruby-2.2.0/gems/rack-1.6.0/lib/rack/deflater.rb:35:in `call'
/Users/USER/.rvm/gems/ruby-2.2.0/gems/rack-1.6.0/lib/rack/auth/basic.rb:25:in `call'
/Users/USER/.rvm/gems/ruby-2.2.0/gems/rack-1.6.0/lib/rack/commonlogger.rb:33:in `call'
/Users/USER/.rvm/gems/ruby-2.2.0/gems/sinatra-1.0/lib/sinatra/base.rb:979:in `block in call'
/Users/USER/.rvm/gems/ruby-2.2.0/gems/sinatra-1.0/lib/sinatra/base.rb:1005:in `synchronize'
/Users/USER/.rvm/gems/ruby-2.2.0/gems/sinatra-1.0/lib/sinatra/base.rb:979:in `call'
/Users/USER/.rvm/gems/ruby-2.2.0/gems/rack-1.6.0/lib/rack/handler/webrick.rb:89:in `service'
/Users/USER/.rvm/rubies/ruby-2.2.0/lib/ruby/2.2.0/webrick/httpserver.rb:138:in `service'
/Users/USER/.rvm/rubies/ruby-2.2.0/lib/ruby/2.2.0/webrick/httpserver.rb:94:in `run'
/Users/USER/.rvm/rubies/ruby-2.2.0/lib/ruby/2.2.0/webrick/server.rb:294:in `block in start_thread'
ERROR: Rack::Utils::OkJson::Error: cannot encode Symbol: :schema_migrations
[2015-05-06 17:28:57] ERROR NoMethodError: undefined method `blank?' for {}:Hash
...........
localhost - - [06/May/2015:17:28:57 BST] "GET /sessions/1568289369/pull/table_names HTTP/1.1" 500 317
-> /sessions/1568289369/pull/table_names
确保使用正确的 ruby 版本（在本例中为 2.0.0），如果您还没有这样做，我建议您安装和使用 RVM。
RVM use 2.0.0
打开两个终端 windows，确保它们都指向 ruby 2.0.0，因为打开一个新终端将恢复到 ruby 的默认版本，通过 [=16] 检查=]
ruby -v
将您的 gem 文件更改为：
gem 'rack','1.0.1'
gem 'sqlite3'
gem 'pg'
gem 'taps'
和运行
bundle
在项目中的一个终端上 运行 sqlite 服务器：
taps server sqlite://db/development.sqlite3 user password
在您项目的第二个终端上 运行:
taps pull postgres://user@localhost/db/development http://user:secret@localhost:5000
这应该可以做到。
然后替换您的 gem 文件并使用您想要的 ruby 版本！
不要使用水龙头，使用 sequel 命令，如：
sequel -C sqlite://db/development.sqlite3 postgres://pgusername:pguserpassword@localhost/development_db
仅供 google = )
我正在尝试将一个小型 SQLite 数据库迁移到 PostgreSQL，以便我可以将它放在 Heroku 上。计划是将本地数据库迁移到 PostgreSQL 实例。一旦我知道它工作正常，我就会将数据库迁移到 heroku。
事实证明这是非常困难的。我不习惯在 Rails 上 Ruby，所以可能错过了所有技巧。
我 运行 Ruby 2.2.0 / Rails 4.2.0 MAC
关于问题的任何想法/
我运行下面的命令从SQLite3迁移到PostgreSQL。请注意 Db:migrate 有效并且数据库模式已就位。我现在只需要将数据放入其中。
taps pull postgres://user@localhost/db/development http://user:secret@localhost:5000
然后我得到以下输出：
Receiving schema Unable to fetch tables information from http://user:secret@localhost:5000. Please check the server log.
在我启动服务的另一个终端中，我得到以下内容，其中包含一个引用 table:
的错误Rack::Utils::OkJson::Error - cannot encode Symbol: :schema_migrations::
$ **taps server sqlite://db/development.sqlite3 USER secret**
== Sinatra/1.0 has taken the stage on 5000 for production with backup from WEBrick
[2015-05-06 17:28:09] INFO WEBrick 1.3.1
[2015-05-06 17:28:09] INFO ruby 2.2.0 (2014-12-25) [x86_64-darwin14]
[2015-05-06 17:28:09] INFO WEBrick::HTTPServer#start: pid=8274 port=5000
127.0.0.1 - USER [06/May/2015:17:28:57 +0100] "GET / HTTP/1.1" 200 - 0.0010
localhost - - [06/May/2015:17:28:57 BST] "GET / HTTP/1.1" 200 31
- -> /
127.0.0.1 - USER [06/May/2015:17:28:57 +0100] "POST /sessions HTTP/1.1" 200 - 0.0158
localhost - - [06/May/2015:17:28:57 BST] "POST /sessions HTTP/1.1" 200 46
- -> /sessions
Rack::Utils::OkJson::Error - cannot encode Symbol: :schema_migrations:
/Users/USER/.rvm/gems/ruby-2.2.0/gems/rack-1.6.0/lib/rack/utils/okjson.rb:427:in `valenc'
/Users/USER/.rvm/gems/ruby-2.2.0/gems/rack-1.6.0/lib/rack/utils/okjson.rb:438:in `block in arrenc'
/Users/USER/.rvm/gems/ruby-2.2.0/gems/rack-1.6.0/lib/rack/utils/okjson.rb:438:in `map'
/Users/USER/.rvm/gems/ruby-2.2.0/gems/rack-1.6.0/lib/rack/utils/okjson.rb:438:in `arrenc'
/Users/USER/.rvm/gems/ruby-2.2.0/gems/rack-1.6.0/lib/rack/utils/okjson.rb:410:in `encode'
/Users/USER/.rvm/gems/ruby-2.2.0/gems/taps-0.3.24/lib/taps/server.rb:157:in `block in <class:Server>'
/Users/USER/.rvm/gems/ruby-2.2.0/gems/sinatra-1.0/lib/sinatra/base.rb:865:in `call'
/Users/USER/.rvm/gems/ruby-2.2.0/gems/sinatra-1.0/lib/sinatra/base.rb:865:in `block in route'
/Users/USER/.rvm/gems/ruby-2.2.0/gems/sinatra-1.0/lib/sinatra/base.rb:521:in `instance_eval'
/Users/USER/.rvm/gems/ruby-2.2.0/gems/sinatra-1.0/lib/sinatra/base.rb:521:in `route_eval'
/Users/USER/.rvm/gems/ruby-2.2.0/gems/sinatra-1.0/lib/sinatra/base.rb:500:in `block (2 levels) in route!'
/Users/USER/.rvm/gems/ruby-2.2.0/gems/sinatra-1.0/lib/sinatra/base.rb:497:in `catch'
/Users/USER/.rvm/gems/ruby-2.2.0/gems/sinatra-1.0/lib/sinatra/base.rb:497:in `block in route!'
/Users/USER/.rvm/gems/ruby-2.2.0/gems/sinatra-1.0/lib/sinatra/base.rb:476:in `each'
/Users/USER/.rvm/gems/ruby-2.2.0/gems/sinatra-1.0/lib/sinatra/base.rb:476:in `route!'
/Users/USER/.rvm/gems/ruby-2.2.0/gems/sinatra-1.0/lib/sinatra/base.rb:601:in `dispatch!'
/Users/USER/.rvm/gems/ruby-2.2.0/gems/sinatra-1.0/lib/sinatra/base.rb:411:in `block in call!'
/Users/USER/.rvm/gems/ruby-2.2.0/gems/sinatra-1.0/lib/sinatra/base.rb:566:in `instance_eval'
/Users/USER/.rvm/gems/ruby-2.2.0/gems/sinatra-1.0/lib/sinatra/base.rb:566:in `block in invoke'
/Users/USER/.rvm/gems/ruby-2.2.0/gems/sinatra-1.0/lib/sinatra/base.rb:566:in `catch'
/Users/USER/.rvm/gems/ruby-2.2.0/gems/sinatra-1.0/lib/sinatra/base.rb:566:in `invoke'
/Users/USER/.rvm/gems/ruby-2.2.0/gems/sinatra-1.0/lib/sinatra/base.rb:411:in `call!'
/Users/USER/.rvm/gems/ruby-2.2.0/gems/sinatra-1.0/lib/sinatra/base.rb:399:in `call'
/Users/USER/.rvm/gems/ruby-2.2.0/gems/rack-1.6.0/lib/rack/deflater.rb:35:in `call'
/Users/USER/.rvm/gems/ruby-2.2.0/gems/rack-1.6.0/lib/rack/auth/basic.rb:25:in `call'
/Users/USER/.rvm/gems/ruby-2.2.0/gems/rack-1.6.0/lib/rack/commonlogger.rb:33:in `call'
/Users/USER/.rvm/gems/ruby-2.2.0/gems/sinatra-1.0/lib/sinatra/base.rb:979:in `block in call'
/Users/USER/.rvm/gems/ruby-2.2.0/gems/sinatra-1.0/lib/sinatra/base.rb:1005:in `synchronize'
/Users/USER/.rvm/gems/ruby-2.2.0/gems/sinatra-1.0/lib/sinatra/base.rb:979:in `call'
/Users/USER/.rvm/gems/ruby-2.2.0/gems/rack-1.6.0/lib/rack/handler/webrick.rb:89:in `service'
/Users/USER/.rvm/rubies/ruby-2.2.0/lib/ruby/2.2.0/webrick/httpserver.rb:138:in `service'
/Users/USER/.rvm/rubies/ruby-2.2.0/lib/ruby/2.2.0/webrick/httpserver.rb:94:in `run'
/Users/USER/.rvm/rubies/ruby-2.2.0/lib/ruby/2.2.0/webrick/server.rb:294:in `block in start_thread'
ERROR: Rack::Utils::OkJson::Error: cannot encode Symbol: :schema_migrations
[2015-05-06 17:28:57] ERROR NoMethodError: undefined method `blank?' for {}:Hash
...........
localhost - - [06/May/2015:17:28:57 BST] "GET /sessions/1568289369/pull/table_names HTTP/1.1" 500 317 -> /sessions/1568289369/pull/table_names
确保使用正确的 ruby 版本（在本例中为 2.0.0），如果您还没有这样做，我建议您安装和使用 RVM。
RVM use 2.0.0
打开两个终端 windows，确保它们都指向 ruby 2.0.0，因为打开一个新终端将恢复到 ruby 的默认版本，通过 [=16] 检查=]
ruby -v
将您的 gem 文件更改为：
gem 'rack','1.0.1'
gem 'sqlite3'
gem 'pg'
gem 'taps'
和运行
bundle
在项目中的一个终端上 运行 sqlite 服务器：
taps server sqlite://db/development.sqlite3 user password
在您项目的第二个终端上 运行:
taps pull postgres://user@localhost/db/development http://user:secret@localhost:5000
这应该可以做到。
然后替换您的 gem 文件并使用您想要的 ruby 版本！
不要使用水龙头，使用 sequel 命令，如：
sequel -C sqlite://db/development.sqlite3 postgres://pgusername:pguserpassword@localhost/development_db
仅供 google = )