Rails - Help with rake task

Question

I have a rake task I need to run in order to sanitize (remove forward slashes) some data in the database. Here's the task:

namespace :db do
  desc "Remove slashes from old-style URLs"
  task :substitute_slashes => :environment do
    puts "Starting"
    contents = Content.all
    contents.each do |c|
      if c.permalink != nil
        c.permalink.gsub!("/","")
        c.save!
      end
    end
    puts "Finished"    
  end
end

Which allows me to run rake db:substitute_slashes --trace

If I do puts c.permalink after the gsub! I can see it's setting the attribute properly. However the save! doesn't seem to be working because the data is not changed. Can someone spot what the issue may be?

Another thing, I have paperclip installed and this task is triggering [paperclip] Saving attachments. which I would rather avoid.

Answer 1

try this:

namespace :db do
  desc "Remove slashes from old-style URLs"
  task :substitute_slashes => :environment do
    puts "Starting"
    contents = Content.all
    contents.each do |c|
      unless c.permalink.nil?
        c.permalink = c.permalink.gsub(/\//,'')
        c.save!
      end
    end
    puts "Finished"    
  end
end

1.) Change != nil to unless record.item.nil? (I don't know if it makes a different, but I've never used != nil. You may want to use .blank? also judging by your code)

2.) Your gsub was malformed. The pattern must be between two / (/ stuff /). The \ is necessary because you need to escape the /.

3.) Bang (!) updates the object in place. I think your biggest issue may be that you are overusing !.

4.) You're also making this very inefficient... You are looking at every record and updating every record. Rails isn't always the best option. Learn SQL and do this in one line:

"UPDATE contents SET permalink = replace(permalink, '/', '');"

If you MUST use Rails:

ActiveRecord::Base.connection.execute "UPDATE contents SET permalink = replace(permalink, '/', '');"

Wow! One query. Amazing! :)