请教用PHP备份MYSQL数据的做法

Question

我们一般会直接用mysqldump来备份数据库（表），那请问用PHP备份MYSQL数据表如何做，特别是当MYSQL数据表非常大的情况。

Answer 1

backup_tables('localhost','username','password','blog');


function backup_tables($host,$user,$pass,$name,$tables = '*')
{

$link = mysql_connect($host,$user,$pass);
mysql_select_db($name,$link);

if($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);
}

foreach($tables as $table)
{
$result = mysql_query('SELECT * FROM '.$table);
$num_fields = mysql_num_fields($result);

$return.= 'DROP TABLE '.$table.';';
$row2 = mysql_fetch_row(mysql_query('SHOW CREATE TABLE '.$table));
$return.= "\n\n".$row2[1].";\n\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\n";
}

$handle = fopen('db-backup-'.time().'-'.(md5(implode(',',$tables))).'.sql','w+');
fwrite($handle,$return);
fclose($handle);
}