从oracle导出并将查询结果下载到PHP的Excel文件中

Question

// Export results
require_once('PHPExcel.php');
$query = "SELECT DISTINCT TITLE, PID, TYPE, SUM(DAYCOUNT) AS tot, ROUND(SUM(DAYCOUNT)/( SELECT SUM(DAYCOUNT) FROM REPORT_LIST_VIEW), 4) AS per FROM REPORT_LIST_VIEW WHERE DAYCOUNT > '0' GROUP BY TITLE, PID, TYPE ORDER BY tot DESC";
if ($result = db_query($query)) {
    // Create a new PHPExcel object
    $objPHPExcel = new PHPExcel();
    $objPHPExcel->getActiveSheet()->setTitle('List of Cities');
    // Loop through the result set
    $rowNumber = 1;
    while ($row = $result->fetchAssoc()) {
        $objPHPExcel->getActiveSheet()->fromArray($row,NULL,'A'.$rowNumber++);
    }
    // Save as an Excel BIFF (xls) file
    $objWriter = PHPExcel_IOFactory::createWriter($objPHPExcel, 'Excel5');
    $objWriter->save('CityList.xls');
}

我在PHP页面中尝试使用此代码将Oracle的查询结果作为Excel文件下载，但是当我浏览到该页面时，它都是空白的，就像挂起一样。

任何线索？