export-all-tables-to-sql.rb

require 'csv'

export_folder = "./export"
FileUtils.mkdir_p(export_folder) unless File.exists?(export_folder)
exported_tables = []
skipped_tables = []

puts "Starting CSV export"
ActiveRecord::Base.connection.tables.each do |table_name|
  file = "#{export_folder}/#{table_name}.csv"

  begin
    klass = table_name.classify.constantize
  rescue NameError
    # If we can't classify the name (e.g. it's namespaced), try to pull it from ActiveRecord::Base.descendants
    klass = ActiveRecord::Base.descendants.find { |d| d.table_name == table_name }

    # If we still can't find it, skip it.
    if klass.nil?
      puts "  !!!  Skipping table #{table_name} (no model)"
      skipped_tables << table_name
      next
    end
  end

  table = klass.all;0 # ";0" stops output.    
  if table.any?
    print "  #{"%.3d" % (exported_tables.count + 1)}. Exporting table #{table_name} (#{klass.name}) to #{file}..."
    exported_tables << table_name
    CSV.open( file, 'w' ) do |writer|
      writer << table.first.attributes.map { |a,v| a }
      table.each do |s|
        writer << s.attributes.map { |a,v| v }
      end
    end
    puts "Done."
  else
    puts "  !!!  Skipping table #{table_name} (no data)"
    skipped_tables << table_name
  end
end

puts "Tables exported: #{exported_tables.join(', ')}"
puts "Tables skipped: #{skipped_tables.join(', ')}"