对于大型数据库，PHPExcel脚本需要很长时间

这是PHP代码，我对PHPExcel了解不多，无法让它运行得更快，理想情况下我不想限制为10000行（在它发送excel文件之前至少需要5分钟）

有什么想法吗

脚本基本上从sqlite数据库中选择所有数据，然后循环第一行的键以添加列标题。
然后循环所有行并设置每个单元格值。
然后添加公式列。
然后将excel数据发送给用户

脚本在：-处运行，因此每次用户进入该页面时，它都会运行此脚本-我认为我应该每天存储数据库，如果已经存储了该数据库，则只需返回文件，否则将再次生成excel

<?php

date_default_timezone_set('Europe/Zurich');

require_once 'phpexcel/Classes/PHPExcel.php';

ini_set('max_execution_time', 900);

$dbname = 'admin';
$fullPath = sprintf('/var/www/fullpathtosqlite/%s.sqlite', $dbname);

$dbh = new PDO('sqlite:' . $fullPath);

$phpExcel = new PHPExcel();
$phpExcel->getProperties()->setTitle('Export : Statistics');
$phpExcel->getProperties()->setCreator('PHPExcel Stats Script');

$sheet = $phpExcel->getActiveSheet();
$sheet->setTitle('stats');

$phpExcel->setActiveSheetIndex(0);

$sql = 'SELECT * FROM (SELECT * FROM statistics ORDER BY timestamp DESC LIMIT 10000) ORDER BY timestamp ASC';

if(!$stmt = $dbh->prepare($sql, array(PDO::ATTR_CURSOR, PDO::CURSOR_SCROLL))) {
    die(var_export($dbh->errorinfo(), TRUE));
}

$stmt->execute();

// Fetch the first row
$row = $stmt->fetch(PDO::FETCH_ASSOC, PDO::FETCH_ORI_NEXT);

$results = array();
// Iterate over the results and print each one in a line
while ($row != false) {
    $results[] = $row;
    // Fetch the next line
    $row = $stmt->fetch(PDO::FETCH_ASSOC, PDO::FETCH_ORI_NEXT);
}

$row = 1;
$col = 0;
foreach ($results[0] as $key => $value) {
    $sheet->setCellValueByColumnAndRow($col, $row, $key);
    $col++;
}

// date
$sheet->setCellValueByColumnAndRow($col, $row, 'date');
$col++;
// time
$sheet->setCellValueByColumnAndRow($col, $row, 'time');
$col++;
// full_date
$sheet->setCellValueByColumnAndRow($col, $row, 'full_date');

$row = 2;
foreach ($results as $result) {
    $col = 0;
    foreach ($result as $key => $value) {
        $sheet->setCellValueByColumnAndRow($col, $row, $value);
        $col++;
    }

    // date
    $sheet->setCellValueByColumnAndRow($col, $row, '=DATE(LEFT(A' . $row . ',4),MID(A' . $row . ',5,2),MID(A' . $row . ',7,2))');
    $col++;
    // time
    $sheet->setCellValueByColumnAndRow($col, $row, '=TIME(MID(A' . $row . ',9,2),MID(A' . $row . ',11,2),MID(A' . $row . ',13,2))');
    $col++;
    // full_date
    $sheet->setCellValueByColumnAndRow($col, $row, '=F' . $row . '+G' . $row);

    $row++;
}

$sheet->getStyle('F2:F' . $row)
      ->getNumberFormat()
      ->setFormatCode('dd/mm/yyyy');
$sheet->getStyle('G2:G' . $row)
      ->getNumberFormat()
      ->setFormatCode('h:mm AM/PM');
$sheet->getStyle('H2:H' . $row)
      ->getNumberFormat()
      ->setFormatCode('dd/mm/yyyy hh:mm');

foreach(range('A','H') as $columnID) {
    $sheet->getColumnDimension($columnID)->setAutoSize(true);
}

header("Content-Type: application/vnd.ms-excel");
header("Content-Disposition: attachment; filename=\"statistics.xls\"");
header("Cache-Control: max-age=0");

$objWriter = PHPExcel_IOFactory::createWriter($phpExcel, "Excel5");
$objWriter->save("php://output");
exit;

---

处理的数据越多，所需时间越长。这就是为什么我们建议将生成大型电子表格的工作分配给后端流程，这样用户在生成电子表格时就不会等待

如果您可以“离线”构建这些大型数据电子表格，那么就这样做；如果可以缓存它们，那么就这样做