通过PHPExcel将Excel表文件中数据导入数据库

<?php
header("Content-Type:text/html;charset=utf-8");
include_once 'PHPExcel.php';
include_once 'PHPExcel/IOFactory.php';

set_time_limit(600);
//文件的目录
$dir = './files/';
$array = scandir($dir);//列出指定路径中的文件和目录
$count = 3832;
$p = $_GET['p'];
if($p <= 1) {
    $p = 1;
}
$countP = $p + 5;
$countP = $countP > $count ? $count : $countP;

for($i = $p; $i<$countP; $i++) {
    $reader = PHPExcel_IOFactory::createReader('Excel5');
    // $resource = $dir . '3815.xls';
    $resource = $dir . $i . '.xls';
    //echo $resource;
    $PHPExcel = $reader->load($resource); // 文件名称
    $sheet = $PHPExcel->getSheetByName('低压线路');//文件下的一个sheet表
    $highestRow = $sheet->getHighestRow(); // 取得总行数
    //echo $highestRow.'<br>';
    //连接数据库
    $dsn = "mysql:host=localhost;dbname=data_info";
    $username = "root";
    $passwd = "";
    $pdo = new PDO($dsn, $username, $passwd);
    $pdo->query("SET NAMES utf8");

    for ($j = 4; $j <= $highestRow; $j++) {
        //取出数据
　　　　 //getCellByColumnAndRow(参数1,参数2)->getValue();      ————获取某行某列的数据值
　　　　 //其中：  参数1：列的位置 参数2: 行的位置
        $name = $sheet->getCellByColumnAndRow(3, $j)->getValue();
        $id = $sheet->getCellByColumnAndRow(7, $j)->getValue();
        $byq = $sheet->getCellByColumnAndRow(8, $j)->getValue();
        $bz = $sheet->getCellByColumnAndRow(11, $j)->getValue();
        $time = $sheet->getCellByColumnAndRow(13, $j)->getValue();
        if ($name) {
            $sql = "insert into low_line_copy(circuit_name, trans_id, trans_name, maintain_group, `time`) values
        ('" . $name . "','" . $id . "','" . $byq . "','" . $bz . "','" . $time . "'); \n";
            echo $sql . '<br>';
            //指定数据存到文件中
            file_put_contents('./a.txt', $i . ',' . $sql . "\r\n", FILE_APPEND);
        }
        //$pdo->exec($sql);
    }
    unset($reader);
}
?>
    <script>
        //每页执行5条，之后跳转
        location.href = "1.php?p=<?=($i);?>";
    </script>