Exporting a CSV File from Rails Console

TIL that creating your own CSV file from Rails console, or, I suppose, anywhere in Ruby isn't that hard.

All you have to do is use the CSV class, which is part of Ruby's standard library.

First decide what data you want to have in your CSV. Perhaps you have a list of users and you want to output their id, name, and GitHub username. (I live in a world where all users have GitHub usernames.)

Open up a Rails console with a little rails c magic. Then queue up your users.

users = User.where.not(github_username: nil)

Determine the location of where you want your file to be stored. If you're doing this on a remote server, you probably want to put the file in a temporary loation. Something like

file = "#{Rails.root}/tmp/#{Date.current}-user_list.csv"

will probably do.

Now, it's time iterate over your users and write to that CSV.

CSV.open(file, 'w') do |csv|
  users.each do |user|
     csv << [user.id, user.name, user.github_username]

And that's pretty much it. Your file will be located at the path you created.

Now, you'll probably also want to grab the file off the remote server, and you would do that with scp, which refers to secure copy.

To copy the file, you'd run a variation of this command from your command line:

scp username@remotehost.com:/path/to/file /local/path/to/file

As long as you can ssh onto your remote server and you have the right paths, you should be good to go!

And that's what I learned today about CSV and scp.