备份mysql数据的php代码

<?php

##################### 
//CONFIGURATIONS  
#####################
// Define the name of the backup directory
define('BACKUP_DIR', './myBackups' ) ; 
// Define  Database Credentials
define('HOST', 'localhost' ) ; 
define('USER', 'testd!b' ) ; 
define('PASSWORD', 'k^[email protected]#VV' ) ; 
define('DB_NAME', 'test123' ) ; 
/*
Define the filename for the sql file
If you plan to upload the  file to Amazon's S3 service , use only lower-case letters 
*/
$fileName = 'mysqlbackup--' . date('d-m-Y') . '@'.date('h.i.s').'.sql' ; 
// Set execution time limit
if(function_exists('max_execution_time')) {
if( ini_get('max_execution_time') > 0 )     set_time_limit(0) ;
}

###########################  

//END  OF  CONFIGURATIONS  

###########################

// Check if directory is already created and has the proper permissions
if (!file_exists(BACKUP_DIR)) mkdir(BACKUP_DIR , 0700) ;
if (!is_writable(BACKUP_DIR)) chmod(BACKUP_DIR , 0700) ; 

// Create an ".htaccess" file , it will restrict direct accss to the backup-directory . 
$content = 'deny from all' ; 
$file = new SplFileObject(BACKUP_DIR . '/.htaccess', "w") ;
$file->fwrite($content) ;

$mysqli = new mysqli(HOST , USER , PASSWORD , DB_NAME) ;
if (mysqli_connect_errno())
{
   printf("Connect failed: %s", mysqli_connect_error());
   exit();
}
 // Introduction information
 $return .= "--\n";
$return .= "-- A Mysql Backup System \n";
$return .= "--\n";
$return .= '-- Export created: ' . date("Y/m/d") . ' on ' . date("h:i") . "\n\n\n";
$return = "--\n";
$return .= "-- Database : " . DB_NAME . "\n";
$return .= "--\n";
$return .= "-- --------------------------------------------------\n";
$return .= "-- ---------------------------------------------------\n";
$return .= 'SET AUTOCOMMIT = 0 ;' ."\n" ;
$return .= 'SET FOREIGN_KEY_CHECKS=0 ;' ."\n" ;
$tables = array() ; 
// Exploring what tables this database has
$result = $mysqli->query('SHOW TABLES' ) ; 
// Cycle through "$result" and put content into an array
while ($row = $result->fetch_row()) 
{
$tables[] = $row[0] ;
}
// Cycle through each  table
 foreach($tables as $table)
 { 
// Get content of each table
$result = $mysqli->query('SELECT * FROM '. $table) ; 
// Get number of fields (columns) of each table
$num_fields = $mysqli->field_count  ;
// Add table information
$return .= "--\n" ;
$return .= '-- Tabel structure for table `' . $table . '`' . "\n" ;
$return .= "--\n" ;
$return.= 'DROP TABLE  IF EXISTS `'.$table.'`;' . "\n" ; 
// Get the table-shema
$shema = $mysqli->query('SHOW CREATE TABLE '.$table) ;
// Extract table shema 
$tableshema = $shema->fetch_row() ; 
// Append table-shema into code
$return.= $tableshema[1].";" . "\n\n" ; 
// Cycle through each table-row
while($rowdata = $result->fetch_row()) 
{ 
// Prepare code that will insert data into table 
$return .= 'INSERT INTO `'.$table .'`  VALUES ( '  ;
// Extract data of each row 
for($i=0; $i<$num_fields; $i++)
{
$return .= '"'.$rowdata[$i] . "\"," ;
 }
 // Let's remove the last comma 
 $return = substr("$return", 0, -1) ; 
 $return .= ");" ."\n" ;
 } 
 $return .= "\n\n" ; 
}
// Close the connection
$mysqli->close() ;
$return .= 'SET FOREIGN_KEY_CHECKS = 1 ; '  . "\n" ; 
$return .= 'COMMIT ; '  . "\n" ;
$return .= 'SET AUTOCOMMIT = 1 ; ' . "\n"  ; 
//$file = file_put_contents($fileName , $return) ; 
$zip = new ZipArchive() ;
$resOpen = $zip->open(BACKUP_DIR . '/' .$fileName.".zip" , ZIPARCHIVE::CREATE) ;
if( $resOpen ){
$zip->addFromString( $fileName , "$return" ) ;
    }
$zip->close() ;
$fileSize = get_file_size_unit(filesize(BACKUP_DIR . "/". $fileName . '.zip')) ; 
$message = <<<msg
  <h2>BACKUP  completed ,</h2><br> 
  the archive has the name of  : <b>  $fileName  </b> and it's file-size is :   $fileSize  .<br>
 This zip archive can't be accessed via a web browser , as it's stored into a protected directory . <br>
  It's highly recomended to transfer this backup to another filesystem , use your favorite FTP client to download the archieve . 
msg;
echo $message ; 

// Function to append proper Unit after file-size . 
function get_file_size_unit($file_size){
switch (true) {
    case ($file_size/1024 < 1) :
        return intval($file_size ) ." Bytes" ;
        break;
    case ($file_size/1024 >= 1 && $file_size/(1024*1024) < 1)  :
        return intval($file_size/1024) ." KB" ;
        break;
    default:
    return intval($file_size/(1024*1024)) ." MB" ;
}
}