代码：

<?phpbackup_tables('localhost','root','root','mysql');/* backup the db OR just a table */
function backup_tables($host,$user,$pass,$name,$tables = '*')
{$link = mysql_connect($host,$user,$pass);mysql_select_db($name,$link);$return  = "-- \n";$return .= '-- MySQL DATABASE DUMPER. Copyright GLS Studio ' . "\n";$return .= "-- \n\n";//get all of the tablesif($tables == '*'){$tables  = array();$result = mysql_query('SHOW TABLES');while($row = mysql_fetch_row($result)) $tables[] = $row[0];}else $tables = is_array($tables) ? $tables : explode(',',$tables);//cycle throughforeach($tables as $table){$result = mysql_query('SELECT * FROM '.$table);$num_fields = mysql_num_fields($result);$return     .= "-- ------------------------------------------------ \n";$return     .= "-- Table structure for table `{$table}` \n\n";// Dump Structure$return     .= "DROP TABLE IF EXISTS `{$table}`; \n";$row2 = mysql_fetch_row(mysql_query('SHOW CREATE TABLE '.$table));$return.= "\n\n".$row2[1].";\n";for ($i = 0; $i < $num_fields; $i++) {while($row = mysql_fetch_row($result)){$return.= 'INSERT INTO '.$table.' VALUES(';for($j=0; $j<$num_fields; $j++) {$row[$j] = addslashes($row[$j]);$row[$j] = ereg_replace("\n","\\n",$row[$j]);if (isset($row[$j])) $return .= '"'.$row[$j].'"' ;else $return .= '""';if ($j<($num_fields-1)) $return.= ','; }$return.= ");\n";}}$return .="\n\n";$return .= "-- Table structure for table `{$table}` \n";$return .= "-- ------------------------------------------------- \n\n\n";}//save file//$handle = fopen('db-backup-'.time().'-'.(md5(implode(',',$tables))).'.sql','w+');//fwrite($handle,$return);//fclose($handle);//add below code to download it as a sql fileHeader('Content-type: application/octet-stream');Header('Content-Disposition: attachment; filename=db-backup-'.time().'-'.(md5(implode(',',$tables))).'.sql');echo $return;
}