Create seed file from data already in the database

Not sure about any existing rake tasks, but you can try running something like this in the rails console & paste the results into your seeds.rb file

(warning: dirty & untested)

c = Category.all

c.each do |cat|
  puts "Category.create(:name => '#{cat.name}')"
end

Adjust for any additional fields you may have.

Hope this helps.

There is a gem called seed_dump, which will do exactly what you want:

• https://github.com/rroblak/seed_dump
• http://rubygems.org/gems/seed_dump

Old question, I have a new one based on @Brian's answer.

If you want to keep the entire row as is:

seedfile = File.open('db/seeds.rb', 'a')

c = Category.all

c.each do |cat|
  seedfile.write "Category.create(#{cat.attributes})\n"
end

seedfile.close

If you want to only write some attributes, change the write line to the following:

seedfile.write "Category.create(#{cat.attributes.slice('attr1', 'attr2', ...})\n"

Or, if you wish all the attributes except some, for example timestamps:

seedfile.write "Category.create(#{cat.attributes.except('created_at', 'updated_at')})\n"