How do I dump data from an entire database in Rails 3.2.11?

Question

In Django, I run the following to dump the entire database to a json file:

django-admin.py dumpdata > data.json

What's the equivalent of the above in Rails 3.2.11? I've tried the following commands but they don't work:

rake db:data:dump_dir dir="my_dir"
rake db:fixtures:dump

The error message for the above is:

user:~/blog$ rake db:fixtures:dump
rake aborted!
Don't know how to build task 'db:fixtures:dump'
/home/user/.rvm/gems/ruby-1.9.3-p362/bin/ruby_noexec_wrapper:14:in `eval'
/home/user/.rvm/gems/ruby-1.9.3-p362/bin/ruby_noexec_wrapper:14:in `<main>'
(See full trace by running task with --trace)

Answer 1

You can try https://github.com/jetthoughts/yaml_db which is a fork of the original yaml_db https://github.com/adamwiggins/yaml_db

Answer 2

Rails has a schema dumping feature (rake db:schema:dump), but no built in data dumping feature.

What database are you using? With MySQL, you can just do a mysqldump.

Edit:

If you wanted to dump JSON data from one model (assuming it wasn't a ton of data), you could do:

MyModel.all.to_json

Answer 3

Based on the comments, this screencast is for you: #342 Migrating to PostgreSQL. It uses the taps gem.