Seed Dump is a Rails 4 plugin that adds a rake task named db:seed:dump.
It allows you to create a db/seeds.rb from the existing data in your database.
Note: if you want to use Seed Dump with Rails 3 or earlier, use version 0.5.3.
Dump all data directly to db/seeds.rb:
$ rake db:seed:dump
Dump only data from the users and products table and dump a maximum amount of 2 records:
$ rake db:seed:dump MODELS=User,Product LIMIT=2
Result:
$ cat db/seeds.rb
# Autogenerated by the db:seed:dump task
# Do not hesitate to tweak this to your needs
products = Product.create!([
{ :category_id => 1, :description => "Long Sleeve Shirt", :name => "Long Sleeve Shirt" },
{ :category_id => 3, :description => "Plain White Tee Shirt", :name => "Plain T-Shirt" }
])
users = User.create!([
{ :id => 1, :password => "123456", :username => "test_1" },
{ :id => 2, :password => "234567", :username => "tes2" }
])
Append to db/seeds.rb instead of overwriting it:
rake db:seed:dump APPEND=true
Use another output file instead of db/seeds.rb:
rake db:seed:dump FILE=db/categories.rb
If you want the dump to use create rather than create!:
rake db:seed:dump CREATE_METHOD='create'
There are more environment variables that can be set— see below for all of them.
Add it to your Gemfile with:
gem 'seed_dump'
Or install it by hand:
$ gem install seed_dump
APPEND: If set to true, append the data to the file instead of overwriting it. Default: false.
CREATE_METHOD: Use the specified create method rather than create! (the default).
EXCLUDE: Comma-separated list of attributes to be excluded from the dump. Default: id, created_at, updated_at.
FILE: Use a different output file. Default: db/seeds.rb.
LIMIT: Dump no more then this amount of data. Default: no limit.
MAX: Split one create action per model into several create actions with MAX elements in each. Default: no limit. Useful for large data dumping to reduce memory usage.
MODEL[S]: A model name or a comma-separated list of models. Default: all models.