CSV ORM

[Jon Egil Strand]

Greetings

Do we have an object relational mapper for csv files?

#data:
first_name;last_name;phone
peter;pan;12345

#ROW ACCESS
person.first_name => "peter"
person.last_name => "pan"



Even nicer if it header_row and separation_character can be specified?


I've considered csvparser-0.1.1 and FasterCSV, but as far as I can tell

- csvparser is a little thin on header_row/sep_char
- FasterCSV's synax
table[:first_name][1]
this kind'o does the job, but I would prefer the implementation of
the datasource to be a bit less visible in the rest of the app


Thank's for your time

JE

 

[James Edward Gray II]

Greetings

Do we have an object relational mapper for csv files?

#data:
first_name;last_name;phone
peter;pan;12345

#ROW ACCESS
person.first_name => "peter"
person.last_name => "pan"

First idea:

#!/usr/bin/env ruby -w

require "rubygems"
require "faster_csv"

require "ostruct"

# load
people = FCSV( DATA, :col_sep => ";",
:headers => true,
:header_converters => :symbol ) do |csv|
csv.inject(Array.new) { |all, person| all + [OpenStruct.new
(person.to_hash)] }
end

# example usage
puts people.map { |person| person.first_name }

__END__
First Name;Last Name;Phone
Peter;Pan;111-1111
Wendy;Darling;222-2222

Second idea, if you are in control of the CSV data:

#!/usr/bin/env ruby -w

require "rubygems"
require "faster_csv"

require "pp"

Person = Struct.newfirst_name, :last_name, hone)

people = [ %w[Peter Pan 111-1111],
%w[Wendy Darling 222-2222] ].inject(Array.new) do |all,
attrs|
all + [Person.new(*attrs)]
end

# dump
csv = FCSV.dump(people)
puts csv
puts

# load
reloaded = FCSV.load(csv)
pp reloaded
puts

# use
puts reloaded.map { |person| person.first_name }

Hope one of those helps.

James Edward Gray II

 

[Gregory Brown]

Gregory and James

Thank you so much for your precise and speedy replies, I am thankful both
for your suggestions and for your effort in building these libraries.

With FasterCSV I espescially like the ability to set

:headers => "my;custom;header"

anything in :csv_options gets passed along to FasterCSV in the code I
suggested, so you might be able to see if that'll be helpful somehow.