Rails 3.1创建记录而不是更新？

Question

I have the following Nokogiri rake task in my Rails (3.1) application:

desc "Import incoming calls"
task :fetch_incomingcalls => :environment do

    # Logs into manage.dial9.co.uk and retrieved list of incoming calls.
    require 'rubygems'
    require 'mechanize'
    require 'logger'

    # Create a new mechanize object
    agent = Mechanize.new

    # Load the dial9 website
    page = agent.get("https://manage.dial9.co.uk/login")

    # Select the first form
    form = agent.page.forms.first
    form.username = 'username
    form.password = 'password'

    # Submit the form
    page = form.submit form.buttons.first

    # Click on link called Call Logs
    page = agent.page.link_with(:text => "Call Logs").click

    # Click on link called Incoming Calls
    page = agent.page.link_with(:text => "Incoming Calls").click

    # Output results to file
    # output = File.open("output.html", "w") { |file|  file << page.search("tbody td").text.strip }

    # Add each row to a new call record
    page = agent.page.search("table tbody tr").each do |row|
      next if (!row.at('td'))
      time, source, destination, duration = row.search('td').map{ |td| td.text.strip }
      Call.create!(:time => time, :source => source, :destination => destination, :duration => duration)
    end
end

The time value is the first row in the table and is unique per call (as we can only receive one call at a time).

What I would like to do is use the time value as the unique identifier for my call logs.

So when scraping the screen, it will "update" the existing calls (which won't change but it's the only way I can think of only importing new calls).

If I set it to:

Call.find_all_by_time(nil).each do |call|

and then:

call.update_attribute(:time, time)

Then it will update the existing records, but I want it to import records that aren't already in our database - based on the time value.

Any help is appreciated!

Answer 1

Do you mean this?

# Add each row to a new call record
page = agent.page.search("table tbody tr").each do |row|
  next if (!row.at('td'))
  time, source, destination, duration = row.search('td').map{ |td| td.text.strip }
  call = Call.find_or_create_by_time(time)
  call.update_attributes({:time => time, :source => source, :destination => destination, :duration => duration})
end