Generate migrations outside Rails - activerecord

Question

I'm using ActiveRecord outside Rails. I would want a program to generate the skeleton of a migration ( as well as a system to collect and maintain them ).
Can anyone make a suggestion?

Answer 1

Also take a look at new active_record_migrations

Answer 2

There is a gem to use Rails Database Migrations in non Rails projects. Its name is "standalone_migrations"
Here is a link
https://github.com/thuss/standalone-migrations

Answer 3

If you do not like to use rake, but still get the system part of ActiveRecord::Migration, then you can use the following to handle the ups and downs from plain ruby (without any rails):
require 'active_record'
require 'benchmark'
# Migration method, which does not uses files in db/migrate but in-memory migrations
# Based on ActiveRecord::Migrator::migrate
def migrate(migrations, target_version = nil)
direction = case
when target_version.nil?
:up
when (ActiveRecord::Migrator::current_version == target_version)
return # do nothing
when ActiveRecord::Migrator::current_version > target_version
:down
else
:up
end
ActiveRecord::Migrator.new(direction, migrations, target_version).migrate
puts "Current version: #{ActiveRecord::Migrator::current_version}"
end
# MigrationProxy deals with loading Migrations from files, we reuse it
# to create instances of the migration classes we provide
class MigrationClassProxy < ActiveRecord::MigrationProxy
def initialize(migrationClass, version)
super(migrationClass.name, version, nil, nil)
#migrationClass = migrationClass
end
def mtime
0
end
def load_migration
#migrationClass.new(name, version)
end
end
# Hash of all our migrations
migrations = {
2016_08_09_2013_00 =>
class CreateSolutionTable < ActiveRecord::Migration[5.0]
def change
create_table :solution_submissions do |t|
t.string :problem_hash, index: true
t.string :solution_hash, index: true
t.float :resemblance
t.timestamps
end
end
self # Necessary to get the class instance into the hash!
end,
2016_08_09_2014_16 =>
class CreateProductFields < ActiveRecord::Migration[5.0]
# ...
self
end
}.map { |key,value| MigrationClassProxy.new(value, key) }
ActiveRecord::Base.establish_connection(
:adapter => 'sqlite3',
:database => 'XXX.db'
)
# Play all migrations (rake db:migrate)
migrate(migrations, migrations.last.version)
# ... or undo them (rake db:migrate VERSION=0)
migrate(migrations, 0)
class ApplicationRecord < ActiveRecord::Base
self.abstract_class = true
end
class SolutionSubmission < ApplicationRecord
end

Answer 4

I have made a minimal example of how to use active record outside of Rails. Rails migrations (Standalone migrations) in non-Rails (and non Ruby) projects.
https://github.com/euclid1990/rails-migration
(Support Rails >= 5.2)
You can refer Rake file in this repo.

Answer 5

There is another gem called otr-activerecord. This gem provides following tasks:
rake db:create
rake db:create_migration[name]
rake db:drop
rake db:environment:set
rake db:fixtures:load
rake db:migrate
rake db:migrate:status
rake db:rollback
rake db:schema:cache:clear
rake db:schema:cache:dump
rake db:schema:dump
rake db:schema:load
rake db:seed
rake db:setup
rake db:structure:dump
rake db:structure:load
rake db:version
All you need to do is to install it and add a Rakefile with content
load 'tasks/otr-activerecord.rake'
OTR::ActiveRecord.configure_from_file! 'config/database.yml'
I prefer this gem over active_record_migrations or Standalone Migration because those two gems depend on railties, which is almost the entire Rails. For example, Nokogiri takes a long time to compile, and takes a lot of spaces.