Rails how to run rake task

How do I run this rake file in terminal/console?

my statistik.rake in lib/tasks

desc "Importer statistikker"
namespace :reklamer do
  task :iqmedier => :environment do
    ...
  end
  task :euroads => :environment do
    ...
  end
  task :mikkelsen => :environment do
    ...
  end
  task :orville => :environment do
    ...
  end
end

You can run Rake tasks from your shell by running:

rake task_name

To run from from Ruby (e.g., in the Rails console or another Rake task):

Rake::Task['task_name'].invoke

To run multiple tasks in the same namespace with a single task, create the following new task in your namespace:

task :runall => [:iqmedier, :euroads, :mikkelsen, :orville] do
  # This will run after all those tasks have run
end

Rake::Task['reklamer:orville'].invoke

or

Rake::Task['reklamer:orville'].invoke(args)

Sometimes Your rake tasks doesn't get loaded in console, In that case you can try the following commands

require "rake"
YourApp::Application.load_tasks
Rake::Task["Namespace:task"].invoke

Have you tried rake reklamer:iqmedier ?

My custom rake tasks are in the lib directory, not in lib/tasks. Not sure if that matters.

If you aren't sure how to run a rake task, first find out first what tasks you have and it will also list the commands to run the tasks.

Run rake --tasks on the terminal.

It will list the tasks like the following:

rake gobble:dev:prime             
rake gobble:dev:reset_number_of_kits                                    
rake gobble:dev:scrub_prod_data

You can then run your task with: rake gobble:dev:prime as listed.

In rails 4.2 the above methods didn't work.

1. Go to the Terminal.

2. Change the directory to the location where your rake file is present.

3. run rake task_name.

4. In the above case, run rake iqmedier - will run only iqmedir task.

5. run rake euroads - will run only the euroads task.

6. To Run all the tasks in that file assign the following inside the same file and run rake all

   task :all => [:iqmedier, :euroads, :mikkelsen, :orville ] do #This will print all the tasks o/p on the screen 
   end
   

As the https://stackoverflow.com/a/5641807/7262646 and https://stackoverflow.com/a/49400110/7262646 described

you have to add

require 'rake'
Rake::Task.clear
YourAppName::Application.load_tasks

on the top of the file.

YourAppName comes from config/applicaion.rb, which is defined as a namespace, such as:

module YourAppName
  class Application < Rails::Application
  end
end

and then you can use

Rake::Task["task_name"].invoke

to invoke your task.