// database back up with email notification
// Use Crontab to automate
// make file executable
 
 
// Define your parameters,
// Best defined in a include file for security purposes
$host = "localhost";
$username = "root";
$password = "password";
$dbname = "database_name"
 
 
// define the file name
$backup = $dbname.date("Y-m-d_H:i:s").'.gz';
// define the path to the file
// we puposely do this outside the web directory
$path = "/home/username/backups/";
// combine into one string
$backup_file = $path.$backup;
 
 
// for email
$email = "myemail@domain.com";
$subject = "MySQL Dump Completed succesfully";
$body = "You MySQL back up for $backup is available at:\n\n $backup_file\n\n"
$body.= "thank you,\n Your friendly Linux Box!";
 
 
// the mysql command
$command = "mysqldump --opt -h $host -u $username -p $password $dbname | gzip > $backup_file";
 
 
// Now that all that is defined lets run the script
if(exec($command)){ // run the command
  if(file_exists($backup_file)){
    mail($email, $subject, $body);
  } else {
    // redefine some variables for mail
    $subject = "MySQL Dump Failed miserably";
    $body = "You MySQL back up for $backup Failed:\n\n $backup_file\n\n"
    $body.= "So Sorry,\n Your friendly Linux Box!";
 
 
    mail($email, $subject, $body);
  }
} else {
  $subject = "Failed to execute command";
  $body = "You MySQL back up for $backup Failed to execute:\n\n $command\n\n"
  $body.= "So Sorry,\n Your friendly Linux Box!";
 
  mail($email, $subject, $body);
}

Here is what you put into your crontab file: we assume you are running this file from outside your web directory (public_html, htdocs) in a folder called backups that you have already created. This runs the script at 1am every sunday

0 1 * * 0 usr/bin/php /home/username/backups/database_backup.php >/dev/null 2>&1

Remember you must have permission to write Cron Jobs on your server. Also, The PHP file must be chmod 755.