create csv in ruby on rails

csv_generate.rb

# Create a CSV in Write Mode
CSV.open("#{Rails.public_path}/file_name.csv", 'wb') do |csv|

  # Add a first row into CSV which is column names
  csv << ['First name', 'Last name', 'Email']

end

# Now we have CSV file created in the public directory of the rails application and also it has columns ready
# Now Let's add some data into it. please note that the data in each cell of the row should be in order with the columns defined.

# Open CSV in Append Mode
CSV.open("#{Rails.public_path}/file_name.csv", 'a+') do |csv|

  # Create rows of data
  csv << ['John', 'Black', '[email protected]'] # next row after first(columns row) 
  csv << ['Cory', 'Anderson', '[email protected]'] # another row

end