Is there an easy way to run a single migration? I don't want to migrate to a certain version I just want to run a specific one.
This question is related to
ruby-on-rails
ruby
migration
If you want to run it from console, this is what you are looking for:
$ rails console
irb(main)> require "#{Rails.root.to_s}/db/migrate/XXXXX_my_migration.rb"
irb(main)> AddFoo.migrate(:up)
I tried the other answers, but requiring without Rails.root
didnt work for me.
Also, .migrate(:up)
part forces the migration to rerun regardless if it has already run or not. This is useful for when you already ran a migration, have kinda undone it by messing around with the db and want a quick solution to have it up again.
This are the steps to run again this migration file "20150927161307_create_users.rb"
Copy and past the class which is in that file to the console.
class CreateUsers < ActiveRecord::Migration
def change
create_table :users do |t|
t.string :name
t.string :email
t.timestamps null: false end
end
end
end
Create an instance of the class CreateUsers
: c1 = CreateUsers.new
change
of that instance: c1.change
Please notice that instead of script/runner
, you may have to use rails runner
on new rails environments.
If you're having trouble with paths you can use
require Rails.root + 'db/migrate/20090408054532_add_foos.rb'
If you've implemented a change
method like this:
class AddPartNumberToProducts < ActiveRecord::Migration
def change
add_column :products, :part_number, :string
end
end
You can create an instance of the migration and run migrate(:up)
or migrate(:down)
on an instance, like this:
$ rails console
>> require "db/migrate/20090408054532_add_part_number_to_products.rb"
>> AddPartNumberToProducts.new.migrate(:down)
Assuming fairly recent version of Rails you can always run:
rake db:migrate:up VERSION=20090408054532
Where version is the timestamp in the filename of the migration.
Edit: At some point over the last 8 years (I'm not sure what version) Rails added checks that prevent this from running if it has already been run. This is indicated by an entry in the schema_migrations
table. To re-run it, simply execute rake db:migrate:redo VERSION=20090408054532
instead.
Method 1 :
rake db:migrate:up VERSION=20080906120000
Method 2:
In Rails Console 1. Copy paste the migration class in console (say add_name_to_user.rb) 2. Then in console, type the following
Sharding.run_on_all_shards{AddNameToUser.up}
It is done!!
If you want to run a specific migration, do
$ rake db:migrate:up VERSION=20080906120000
If you want to run migrations multiple times, do
# use the STEP parameter if you need to go more than one version back
$ rake db:migrate:redo STEP=3
If you want to run a single migration multiple times, do
# this is super useful
$ rake db:migrate:redo VERSION=20080906120000
(you can find the version number in the filename of your migration)
Edit: You can also simply rename your migration file, Eg:
20151013131830_my_migration.rb
-> 20151013131831_my_migration.rb
Then migrate normally, this will treat the migration as a new one (usefull if you want to migrate on a remote environment (such as staging) on which you have less control.
Edit 2: You can also just nuke the migration entry in the database. Eg:
rails_c> q = "delete from schema_migrations where version = '20151013131830'"
rails_c> ActiveRecord::Base.connection.execute(q)
rake db:migrate
will then rerun the up
method of the nuked migrations.
As of rails 5
you can also use rails
instead of rake
Rails 3 - 4
# < rails-5.0
rake db:migrate:up VERSION=20160920130051
Rails 5
# >= rails-5.0
rake db:migrate:up VERSION=20160920130051
# or
rails db:migrate:up VERSION=20160920130051
Looks like at least in the latest Rails release (5.2 at the time of writing) there is one more way of filtering the migrations being ran. One can pass a filter in a SCOPE
environment variable which would be then used to select migration files.
Assuming you have two migration files 1_add_foos.rb
and 2_add_foos.run_this_one.rb
running
SCOPE=run_this_one rails db:migrate:up
will select and run only 2_add_foos.run_this_one.rb
. Keep in mind that all migration files matching the scope will be ran.
Source: Stackoverflow.com