A migration can be manually run from the rails console. In 99% of cases you are
going to be better off using the migration CLI that Rails provides (e.g. rails db:migrate
, rails db:rollback
, etc.).
If you are in a hyper-specific scenario where you need to run the up
or the
down
of a migration without the migration-table check, then you'll want to
consider this approach.
First, connect to the rails console: rails c
. Then require your migration
file.
> require "./db/migration/20200220181733_some_migration.rb"
#=> true
You'll now have access to the SomeMigration
constant. Create an instance of this and then run either the up
-side of the migration:
> SomeMigration.new.up
#=> ... # a bunch of migration output
or the down
-side of it:
> SomeMigration.new.down
#=> ... # a bunch of migration output