php 从 mysql 导出 csv

Question

我有脚本应该从数据库中导出 .csv 文件。问题是它会将导出保存到特定的 ($f) 文件，但不会下载正确的文件(脚本下载空文件)

    <?php
//load the database configuration file
include '../secure/db_connect.php';

//get records from database

$sql_list = "SELECT * FROM `hakom` ORDER BY id DESC";
$sql_list_result = $mysqli->query($sql_list);



if($sql_list_result->num_rows > 0){
    $delimiter = ",";
    $filename = "members_" . date('Y-m-d') . ".csv";

    //create a file pointer
    $f = fopen('hakom_export.csv', 'w');

    //set column headers
    $fields = array('ID', 'MSISDN_');
    fputcsv($f, $fields, $delimiter);

    //output each row of the data, format line as csv and write to file pointer
    while($row = $sql_list_result->fetch_assoc()){

        $lineData = array($row['ID'], $row['MSISDN_']);
        fputcsv($f, $lineData, $delimiter);
    }

    //move back to beginning of file
    fseek($f, 0);

    //set headers to download file rather than displayed
    header('Content-Type: text/csv');
    header('Content-Disposition: attachment; filename="' . $filename . '";');

    //output all remaining data on a file pointer
    fpassthru($f);
}
exit;

?>

我遵循 this page 上的教程

Answer 1

您以只写方式打开文件...

$f = fopen('hakom_export.csv', 'w');

来自 fopen 手册页...

'w' Open for writing only; place the file pointer at the beginning of the file and truncate the file to zero length. If the file does not exist, attempt to create it.

将模式改为w+

$f = fopen('hakom_export.csv', 'w+');

'w+' Open for reading and writing; place the file pointer at the beginning of the file and truncate the file to zero length. If the file does not exist, attempt to create it.