Rails 5 scheduler to update database once a day

Question

I\'m new to rails and want to run a batch file/schedule task daily once at midnight that checks which entries have expired. Every record in the table has a closing_date and

Answer 1

In brief: You can use whenever Gem for this purpose.

You need to create a rake task for where you will write your SQL. Then schedule it as cron job using whenever

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Detailed explanation

First step will be creating a rake task. You can do this using the console

rails g task my_namespace my_task1 

This will create a file named my_namespace.rake in the lib/tasks folder with initial content like

namespace :my_namespace do
  desc "TODO"
  task task1: :environment do
    # Your code will go here
  end

end

You can check whether your task is running properly by running

rake my_namespace:task1 

in the console.

Now you need to schedule the job using the whenever gem.

1. gem 'whenever', :require => false in Gemfile.
2. Run bundle install
3. run wheneverize command in terminal. This will create a schedule.rb file in config folder .

4. Add the following code to schedule your rake task:

   every 1.day, at: '8:00 pm' do
     rake "my_namespace:task1"
   end
   

5. Run this command: whenever --update-crontab. In case your environment is development, use command: whenever --update-crontab --set environment='development' (see this question.

6. run crontab -l to check whether cron job has been added.