Run rake task with Multiple databases

rubyonrails-talk
1

When running generators and migration we can mention name of database in case of multiple databases like this → bin/rails generate migration CreateDogs name:string --database animals

is there anything similar for running one time rake tasks? where we can mention name of db to connect with like this.

bin/rake one_time_tasks:testing --database animals

Is there any plans in near future by rails to support this?

2

Hello there, First, create a custom rake task that takes a database name as an argument. You can do this by creating a new .rake file in your Rails project’s lib/tasks directory. Let’s name this task one_time_tasks.rake :

lib/tasks/one_time_tasks.rake

namespace :one_time_tasks do desc ‘Run one-time tasks with a specific database connection’ task :testing, [:database] => :environment do |_, args| database_name = args[:database] || ‘default_database’ # Use ‘default_database’ if no database name is provided

# Establish a connection to the specified database
ActiveRecord::Base.establish_connection(database_name.to_sym)

# Your one-time task code goes here
# For example, you can call your custom method or do any necessary work
# MyOneTimeTask.run

# Close the connection when done (optional)
ActiveRecord::Base.connection.close

end end You can now run your custom rake task and specify the database connection using the --database option: bin/rake one_time_tasks:testing[–database=animals]

I hope this will be helpful.

1 Like
3

You could follow the examples in the Rails database tasks to create a task that works the same a rails db:migrate:animals, but if your task is just a one-time task, it’s probably easier to just create a class and execute it with rails runner.

class FixDogData
  def fix_dogs(dogs_to_fix=Dogs.all)
    # do stuff
  end
end

then from the command line run

rails runner FixDogData.new.fix_dogs