How to append data to csv file

Question

I want to append data to csv file. I get that data from user using html form. My current code adds data to csv file but it does not append. So when user enters their detail hit register button then it erase the previously added data the insert the new one in that place. So how can I append new data so that it saves in the next row and keeps the rest of the data in place?

Here is what I am doing.

full_name = params["full_name"]
email = params["email"]
phone = params["phone"]
organization = params["organization"]
job = params["job"]
diet = params["diet"]
address = params["address"]
code = params["code"]
city = params["city"]
cost_pool = params["cost_pool"]

CSV.open("participants_info.csv", "wb") do |csv|
  csv << [full_name, email, phone, organization, job, diet, address, code, city, cost_pool]
end

Answer 1

``a'' Write-only, starts at end of file if file exists, otherwise creates a new file for writing.

``a+'' Read-write, starts at end of file if file exists, otherwise creates a new file for reading and writing

use CSV.open("participants_info.csv", "a+")

Answer 2

Open file in append mode (ab)

CSV.open("participants_info.csv", "ab") do |csv|
#...
end

Answer 3

File.open('filename', 'a'){ |outfile|
  CSV::Writer.generate(outfile) do |csv|
    csv << ['c1', nil, '', '"', "\r\n", 'c2']
  end
}