Fastercsv and associated records

Rails
1

Hi,
I try to import data with a rake-task from a csv-file into a model
like:

provider, which has_many :rates

and

rate, which belong_to: provider

I do the following:

namespace :db do
desc “load data from csv”
task :load_csv_data => :environment do
require ‘fastercsv’

FasterCSV.foreach("importdata/tarifs.csv",
  :headers => true, :col_sep => ',') do |row|

  Provider.find_or_create_by_name(
    :name => row['Provider_Name'],
    :hotline => row['Hotline'],
    :email => row['Email']
    )

  Rate.find_or_create_by_name(
    :provider => lambda {
                 Provider.find_by_name(row['Provider_Name']) },
    :name => row['Rate_Name'],
    :preis => row['Preis']
    )
end

end
end

But the association-key (provider_id) in the table “rates” won’t be
writen to the database! I also tried accessing directly provider_id

:provider_id => lambda
{ Provider.find_by_name(row[‘Provider_Name’]) },

but didn’t succeed. Any help is appreciated.

Thanks,
Harm

2

But the association-key (provider_id) in the table “rates” won’t be
writen to the database! I also tried accessing directly provider_id

Why are you using lambda ?

Fred

3

On Mar 6, 6:00 pm, Frederick C. [email protected]
wrote:

But the association-key (provider_id) in the table “rates” won’t be
writen to the database! I also tried accessing directly provider_id

Why are you using lambda ?

it came from an earlier solution

Actually I need to fill the column “provider_id” in the table “rates”
with the associated key-id from the table “provider”!

When I do something like:

  Rate.find_or_create_by_name(
    :provider_id => Provider.find_by_name(row['Provider_Name']),
    :name => row['Rate_Name'],
    :preis => row['Preis']
    )

the column just does not get filled.

Harm

4

On Mar 6, 9:12 pm, harm [email protected] wrote:

On Mar 6, 6:00 pm, Frederick C. [email protected]
wrote:

    )

the column just does not get filled.

When filling an id column like that you should probably be passing an
id rather than a Provider object (although :provider =>
Provider.find_by_name(…) should be ok).
Sounds like you should break this down into smaller steps so that you
see where it is going wrong (eg so that you can check whether a
provider is being found at all)

Fred

5

When filling an id column like that you should probably be passing an
id rather than a Provider object (although :provider =>
Provider.find_by_name(…) should be ok).
Sounds like you should break this down into smaller steps so that you
see where it is going wrong (eg so that you can check whether a
provider is being found at all)

I also thought that and finaly did the trick! Now I do something like:

FasterCSV.foreach("importdata/tarife.csv", :headers =>

true, :col_sep => ‘,’) do |row|
Anbieter.find_or_create_by_name( :name =>row[‘Anbieter_Name’] )

  associated_anbieter  =

Anbieter.find_by_name(row[‘Anbieter_Name’])
associated_kategorie =
Kategorie.find_by_name(row[‘Kategorie’])
associated_netz = Netz.find_by_name(row[‘Netz’])

  Tarif.create(
    :anbieter_id  => associated_anbieter.id,
    :kategorie_id => associated_kategorie.id,
    :netz_id      => associated_netz.id,
    :name         => row['Tarif_Name'] )
end

Probably not really a beauty but working. Anyway thanks for your
feedback.