php实现mysql数据库备份类

if(is_null($tableName)){//backup all table in the db    
$this->_backupAllTable($dbName);    
return;    
}    
if(is_string($tableName)){    
(strlen($tableName)==0) && die('....');    
$this->_backupOneTable($dbName,$tableName);    
return;    
}    
if (is_array($tableName)){    
foreach ($tableName as $table){    
( (!is_string($table)) || strlen($table)==0 ) && die('....');    
}    
$this->_backupSomeTalbe($dbName,$tableName);    
return;    
}    
}    

function restoreDb($dbName,$tableName=null){    
( (!is_string($dbName)) || strlen($dbName)==0 ) && die('$dbName must be a string value');    
//step1:检查是否存在数据库 并连接：    
@mysql_select_db($dbName) || die("the database <b>$dbName</b> dose not exists");    
//step2:检查是否存在数据库备份目录    
$dbDir = $this->_dataDir.DIRECTORY_SEPARATOR.$dbName;    
!is_dir($dbDir) && die("$dbDir not exists");    
//step3:start restore    
$this->_TableBak = new TableBak($this->_mysql_link_id,$dbDir);    
if(is_null($tableName)){//backup all table in the db    
$this->_restoreAllTable($dbName);    
return;    
}    
if(is_string($tableName)){    
(strlen($tableName)==0) && die('....');    
$this->_restoreOneTable($dbName,$tableName);    
return;    
}    
if (is_array($tableName)){    
foreach ($tableName as $table){    
( (!is_string($table)) || strlen($table)==0 ) && die('....');    
}    
$this->_restoreSomeTalbe($dbName,$tableName);    
return;    
}    
}    

function _getTableList($dbName)    
{    
$tableList = array();    
$result=mysql_list_tables($dbName,$this->_mysql_link_id);