yii cdbComand 分页offset,limit 不可复用 [ 求助交流 ]

$command = Yii::app()->db->createdCommand()->from('user');
$page = 1;
$pageSize = 10000;    //每次取1万条数据
$command->limit($pageSize);
do {
    $offset = ($page-1)*$pageSize;
    echo $page . ' ' . $offset . "\n";
    $command->offset($offset);
    echo "offset:" .  $command->offset . "\n" . $command-> text . "\n";
    $result = self::$command->queryAll() ;
    $count = count($result);
    $page++;
}While($count == $pageSize);

这是个死循环, 可以看到$command -> offset 一直在变,而$comand->text一直不变,一直在查询同一条语句