Manually Run A Migration From Rails Console

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

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