将db备份为xml时遇到mysqldump问题(Trouble with mysqldump when backing up db as xml)

我正在尝试使用mysqldump备份我的一个数据库，并且我正在尝试将其导出到已存在的xml文件中。这是我有的：

<?php $dbUser = 'user'; // db User $dbPass = 'pass'; // db User Password $dbName = 'db'; // db name $dest = $_SERVER['DOCUMENT_ROOT'] . 'backup'; // Path to directory class MySQLDump { private $cmd; function MySQLDump($dbUser,$dbPass,$dbName,$dest) { $fname = $dbName.'.xml'; $this->cmd='mysqldump -X -u'.$dbUser.' -p'.$dbPass.' '.$dbName. ' >'.$dest.'/'.$fname; } public function backup() { system($this->cmd, $error); if($error) { trigger_error ('Backup failed: ' . $error . '<br />Attempted: ' . $this->cmd); } } } // end class def $mysqlDump = new MySQLDump($dbUser, $dbPass, $dbName, $dest); $mysqlDump->backup(); ?>

这总是会生成backup功能中抛出的错误。以下是$cmd输出的示例：

mysqldump -X -udan -pdanPass danDB >/var/www/prod/dan/web/backup/danDB.xml

知道出了什么问题吗？我从来没有真正使用过mysqldump所以我不确定我是否正确接近它。任何帮助是极大的赞赏。

I'm trying to backup one of my databases with mysqldump and I'm trying to export it to an xml file which already exists. Here is what I have:

<?php $dbUser = 'user'; // db User $dbPass = 'pass'; // db User Password $dbName = 'db'; // db name $dest = $_SERVER['DOCUMENT_ROOT'] . 'backup'; // Path to directory class MySQLDump { private $cmd; function MySQLDump($dbUser,$dbPass,$dbName,$dest) { $fname = $dbName.'.xml'; $this->cmd='mysqldump -X -u'.$dbUser.' -p'.$dbPass.' '.$dbName. ' >'.$dest.'/'.$fname; } public function backup() { system($this->cmd, $error); if($error) { trigger_error ('Backup failed: ' . $error . '<br />Attempted: ' . $this->cmd); } } } // end class def $mysqlDump = new MySQLDump($dbUser, $dbPass, $dbName, $dest); $mysqlDump->backup(); ?>

This always generates the error thrown in the backup function. Here is a sample of $cmd's output:

mysqldump -X -udan -pdanPass danDB >/var/www/prod/dan/web/backup/danDB.xml

Any idea what's going wrong? I've never really used mysqldump so I'm not sure if I'm approaching this correctly. Any help is greatly appreciated.