Is there a rake task that shows the pending migrations in a rails app?
Might not quite be what OP is asking for, but if you just need to quickly check if any migrations are pending for use in a rake task, without resorting to
rake db:migrate:status | grep down (might not work if you're on Windows)
ActiveRecord::Migration.check_pending! (raises ActiveRecord::PendingMigrationError that you need to rescue)
you can use needs_migration? method: https://apidock.com/rails/v4.0.2/ActiveRecord/Migrator/needs_migration%3F/class
This command will list all migrations with their status (UP
or DOWN
)
Rails 3 and 4
rake db:migrate:status
Rails 5
rake db:migrate:status
# Or
rails db:migrate:status
If you want to see how much migration is done or pending you can see using below command.
rails db:migrate:status
More on this link: Rails Active Record Migration
There is rake db:abort_if_pending_migrations
(at least in Rails 2.3.3, not sure when it was introduced). The description says 'Raises an error if there are pending migrations'. This seems to be used more as a prerequisite for other tasks, but I'm guessing you could use it for your purposes.
EDIT: Here is an example of the output after having just generated and not run a 'test' migration
rails_project theIV$ rake db:abort_if_pending_migrations
(in /Users/theIV/Sites/rails_project/)
You have 1 pending migrations:
20090828200602 Test
Run "rake db:migrate" to update your database then try again.
Following command to check migration status:
rake db:migrate:status
OR
when you run your server, it will display a message to run your pending migration first.
If you need a bash one-liner to determine whether to run a migration or not (e.g., only migrate in a Heroku release phase command when there is a pending migration), this works:
(rails db:migrate:status | grep "^\s*down") && rails db:migrate || echo "No pending migrations found."