Updating model while reading CSV

Rails
1

Hello all,
I was wondering how to update an existing table column when reading in a
CSV? I’m using FasterCSV and my controller method is this…

  • Import Controller -
    def process_csv

    set file name

    file = params[:import][:file]
    rowcount = 0

    Import.transaction do
    FasterCSV.parse(file,
    :headers => true,
    :header_converters => :symbol ) do |row|
    Import.create!(row.to_hash)
    rowcount += 1
    end
    end

    if successful then display, then redirect to index page

    flash[:notice] = “Successfully added #{rowcount} project(s).”
    redirect_to :action => :index

    rescue => exception
    file_name = params[:import][‘file’].original_filename
    file_parts = params[:import][‘file’].original_filename.split(’.’)
    ext = file_parts[1]

    if ext != ‘csv’
    error = “CSV file is required”
    else
    error = ERB::Util.h(exception.to_s) # get the error and HTML
    escape it
    end

    If an exception in thrown, the transaction rolls back and we end

up in this
# rescue block

flash[:error] = "Error adding projects to Import table. (#{error}).

Please try again. "

redirect_to :action => :new

end

As I read the CSV file, I wish to update a column in the model, mainly
“ProjectType” as the record is being created.

The CSV file does not have this information and there’s no possibility
that it’ll ever have it.

Thank you for any help.

JohnM

2

Hey John,

Last week I wrote this code to allow you to easily create models/
records using FasterCSV… it doesn’t directly answer your question,
but it might help or at least give you some ideas:
http://pastie.org/676681

If it looks this would be useful to you or others I can post it on
github; I also have a test suite for it. - pat

On Oct 29, 12:52 pm, John M. [email protected]

3

Sorry… forgot to mention the way it works is:

  • the first row of the CSV is taken as a list of column names
  • the remaining csv rows are data for new models
  • if your model contains a column/attribute matching one of the csv
    column names, it will be loaded
  • each new record is yielded to a block provided.