Rake Task - table rename - DUMP - MySQL Table

backup.rb

namespace :db do
  desc "swap table names and backup  data to sql."
  task :backup => [:environment] do
# can return if any condition fails.
    begin
      base_path = Rails.root
      backup_location = File.join(base_path, 'backups')
      FileUtils.mkdir_p(backup_location) # create backup folder if doesn't exists
      filename = (Dir.glob("#{backup_location}/*.{sql}").count + 1).to_s + '_appended_filename.sql'
      backup_file = File.join(backup_location, filename)
      db_config = Model.connection_config
      o_tblname = Model1.tablename # Or Direct table_names say 'foo' can be used.
      n_tblname = Model2.tablename # Or Direct table_names say 'foo_backup' can be used.
      Model.connection.execute("delete from #{n_tblname}")
      Model.execute("RENAME TABLE #{o_tblname} TO temp")
      Model.execute("RENAME TABLE #{n_tblname} TO #{o_tblname}")
      Model.connection.execute("RENAME TABLE temp TO #{n_tblname}")
      `mysqldump -u#{db_config[:username]} -p#{db_config[:password]} --compact
       -t #{db_config[:database]} #{n_tblname} > #{backup_file}`
# This will grab only data NOT Schema of the table Keep it in Mind
      Model.connection.execute("delete from #{n_tblname}")
      raise "Unable to make DB backup!" if ($?.to_i > 0)
#`gzip -9 #{backup_file}` # If Required compress it. 
    rescue Exception => e
      puts e.backtrace
    end
  end
end