Run migrations from rails console

Question

Is there a way to run rake commands for db:migrate and db:rollback on the console?

It sucks to wait for the rails environment to load!

score 122 · Answer 1 · edited Apr 19 '19 at 16:31

122

In the console:

ActiveRecord::Migration.remove_column :table_name, :column_name

To update your schema.rb file after running migrations from the console, you must run rails db:migrate

edited Apr 19 '19 at 16:31

Weston Ganger

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answered May 10 '14 at 18:49

Homan

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@WestonGanger how? – nruth Feb 10 '18 at 13:46
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@nruth not sure that weston is correct here. I find that any time I run these commands, then I might have to do `reload!` to get the effect in the console, and having finished with the console, as long I exit the console, I do rails db:migrate, and it migrates them, and updates db/schema.rb . Really good to look at db/schema.rb . it shows all your tables. `rails db:migrate` updates `schema.rb` for you, at least I think that's what i've found. – barlop Apr 18 '19 at 15:12
@WestonGanger care to comment?(as your comment is under question) – barlop Apr 18 '19 at 15:43
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@barlop @nruth. The migration occurs as soon as this command is run and changes the database, the schema however will not be updated. Running `rails db:migrate` can automatically update the schema. However this is an extra step that is not in the answer. – Weston Ganger Apr 19 '19 at 16:25
@WestonGanger yeah but since you can do rails db:migrate, that's not manually updating the schema.rb file. That's automatically updating it. – barlop Apr 19 '19 at 19:00

score 89 · Accepted Answer · edited Mar 08 '23 at 10:26

89

Rails <= 4

This will allow you to migrate without reloading the whole rails environment:

ActiveRecord::Migrator.migrate "db/migrate"

and rollback:

# 3 is the number of migrations to rollback, optional, defaults to 1
ActiveRecord::Migrator.rollback "db/migrate", 3

Rails >= 5 (thanks to @gssbzn, his answer is below)

Migrate :

ActiveRecord::MigrationContext.new("db/migrate").migrate

And rollback :

# 3 is the number of migrations to rollback, optional, defaults to 1
ActiveRecord::MigrationContext.new("db/migrate").rollback 3

edited Mar 08 '23 at 10:26

Noach Magedman

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answered Sep 02 '11 at 17:49

Benoit Garret

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Note that if you're using Mongoid, it's the same: `Mongoid::Migrator.migrate "db/migrate"` – Josh Leitzel Sep 05 '12 at 18:00
This is perfect to add to your test_helper.rb in Rails apps – Weston Ganger Oct 07 '16 at 19:28
Received error, bash: ActiveRecord::Migrator.migrate: command not found... using Rails 2.3.18, ruby 1.9.3p551, Now executed after executing the command inside the rails console. – vidur punj Feb 01 '18 at 11:26
In case for some weird reasons your migrations aren't located in `'db/migrate'`, use `ActiveRecord::Tasks::DatabaseTasks.migrations_paths` in its place – Feb 15 '18 at 02:43
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This is correct for Rails 4, but doesn't work for later versions – Shai Coleman Jan 30 '20 at 17:35
See @gssbzn's answer for compatibility with rails 5.2+ – mikemachado Apr 28 '20 at 21:03
Rollback for above 5 - `ActiveRecord::MigrationContext.new("db/migrate").rollback` - not mentioned but also works – oklas Jun 03 '20 at 12:00
This worked for Rails 5 using this command ActiveRecord::Migrator.migrate "db/migrate" – Taimoor Changaiz Jul 11 '20 at 09:29
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For newer Rails versions, you also need to pass `schema_migration`: `ActiveRecord::MigrationContext.new(ActiveRecord::Migrator.migrations_paths, ActiveRecord::Base.connection.schema_migration)` – pamit Mar 17 '21 at 05:35

kizzx2 · Answer 3 · 2016-03-12T04:50:20.817

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Another way that I find neater to just run some migration command from console is this:

ActiveRecord::Schema.define do
  create_table :foo do |t|
    t.string  :bar
    t.timestamps
  end
end

This has the advantage that the contents inside the block is compatible with just copy and pasting random contents from a real migration file / schema.rb.

edited Mar 12 '16 at 04:50

answered Mar 18 '15 at 03:15

kizzx2

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I've found this really helpful in diagnosing some db-specific issues with migrations. Thank you! – AJFaraday Sep 03 '19 at 10:15

score 13 · Answer 4 · answered Oct 10 '18 at 11:18

13

For rails 5.2 the accepted answer has been removed and replaced with

ActiveRecord::MigrationContext.new("db/migrate").migrate

Please be aware as this may also change for future versions of rails as they work to add multiple database connections

answered Oct 10 '18 at 11:18

Gus

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score 13 · Answer 5 · answered Jan 30 '20 at 17:34

13

For Rails 5 and Rails 6:

ActiveRecord::Base.connection.migration_context.migrate

For Rails 3 and Rails 4:

ActiveRecord::Migrator.migrate 'db/migrate'

answered Jan 30 '20 at 17:34

Shai Coleman

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This is the best answer for Rails 5 & 6, because it uses existing methods to get the migration context (instantiating it directly may not be reliable). – Kelvin Jan 05 '22 at 17:19

score 6 · Answer 6 · answered Jun 18 '18 at 21:25

6

I needed to pretend a migration was run to unblock a deploy, this can be done with:

class Mig < ActiveRecord::Base; self.table_name = 'schema_migrations';end
Mig.create! version: '20180611172637'

answered Jun 18 '18 at 21:25

grosser

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score 5 · Answer 7 · answered Sep 02 '11 at 17:50

5

You can use the %x[command]

%x[rake db:migrate]

answered Sep 02 '11 at 17:50

dexter

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That defeats the purpose to not have to wait for rails to load. – rafamvc Oct 04 '11 at 21:23
@rafamvc yes agreed! That's why I think Benoit's answer is better :) – dexter Oct 05 '11 at 04:15

score 1 · Answer 8 · answered Dec 17 '21 at 10:36

1

To run single migration

ActiveRecord::Migration.add_column(:table_name, :column_name, :data_type)

To run all migrations

ActiveRecord::Migrator.migrate('db/migrate')

To rollback n migrations

ActiveRecord::Migrator.rollback('db/migrate', n)

answered Dec 17 '21 at 10:36

Rakesh

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score 0 · Answer 9 · answered Sep 13 '13 at 09:17

I created a method in my .irbrc file that runs migrations then reloads the console:

def migrate
  if defined? Rails::Console # turn off info logging for Rails 3
    old_log_level = ActiveRecord::Base.logger.try(:sev_threshold)
    ActiveRecord::Base.logger.sev_threshold = Logger::WARN
  end
  reload! && migations_ran = true if ActiveRecord::Migrator.migrate(Rails.root.join("db/migrate")).any?
  ActiveRecord::Base.logger.sev_threshold = old_log_level if defined? old_log_level
  migations_ran ||= nil # useful exit status
end

See the entire file here: https://gist.github.com/imme5150/6548368