Ruby script to save records into Rails

Question

I am trying to run a ruby script that parses a text file with album name, artist name, year on each line. It should then save a new record into a Rails model called Album.

(buildDB.rb)

fh = File.open('albums.txt')

while line = fh.gets
    if ( line =~ /^(.+)\~\s(.+) \(\'(\d\d)\)/ )
        a = Album.new
        a.name   = $1
        a.artist = $2
        a.year   = $3
        a.save
    end
end

I am running ruby buildDB.rb in terminal which produces the message

buildDb.rb:12:in '<main>': uninitialized constant Album (NameError)

This made me think that the script could not find the model. So I tried loading the rails environment by using

require "C:/ruby192/www/Project02/config/environment.rb"

at the top of the ruby script. The script will run without errors but nothing is committed to the sqlite database. I can also run find on the already existing Albums, it just seems I can't create new ones.

I am a rails noob so, there probably is a better way to do this (seeds.rb or a rake task maybe). Any help or a direction to look into would be greatly appreciated.

drummondj · Accepted Answer · 2011-11-04 15:37:20Z

1

I would use a rake task:

task :create_albums => :environment do
  fh = File.open('albums.txt')

  while line = fh.gets
    if ( line =~ /^(.+)\~\s(.+) \(\'(\d\d)\)/ )
      a = Album.new
      a.name   = $1
      a.artist = $2
      a.year   = $3
      a.save!
    end
  end
  fh.close
end

I added a ! to the save method so that any errors will throw an exeception. Also, make sure you close your files.

answered Nov 4, 2011 at 15:37

drummondj

1,4831 gold badge10 silver badges11 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Josh Frankel Over a year ago

Actually the addition of the bang provided me with part of the problem. I had the model attribute year set on presence => true, but one of the returned years from the regex was empty. This threw an error on the script

Josh Frankel Over a year ago

Awesome! Got it working and learned a little about rake tasks. Thanks drummondj!

Simmo · Accepted Answer · 2011-11-04 15:43:23Z

0

Rake task is the way ahead. I would use FasterCSV as it will handle some of the data import for you.

namespace :import do
  desc "Import from a csv file"
  task :album_csv, [:filename] => :environment do |task, args|

  lines = FasterCSV.read(args[:filename]) rescue nil
  if lines
    lines.slice!(0) # remove the CSV header if there is one
    puts "# Processing #{lines.count} records"
    lines.each do |line|
      a = Album.new
      a.name   = line[0]
      a.artist = line[1]
      a.year   = line[2]
      a.save!
    end
  end
end

You can then call your rake task as:

rake import:album_csv[filename]

answered Nov 4, 2011 at 15:43

Simmo

1,72919 silver badges39 bronze badges

Collectives™ on Stack Overflow

Ruby script to save records into Rails

2 Answers 2

2 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

2 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related