php 将 MySql 导出到 excel 表不起作用

Question

我收到的错误消息是标题。我正在使用 mysqli_ 我在空白页上使用 mysql_ 来测试它。当我把它放到我真实页面上的点击中时，它告诉我我不能使用 mySql_，因为它太旧了，所以将它转换为 mySqli_。我现在收到的错误消息是：

“警告：无法修改标头信息 - 标头已由 （输出开始于 /xx/xxx/xxx.php:183）在 /xxx/xxx/xxx.php 在线 232 警告：无法修改标头信息 - 标头已发送 通过（输出开始于 /xxx/xxx/xxx.php:183）在 /xxx/xxx/xxx.php 上 第 233 行致命错误：调用未定义的函数 outputcsv() /xxx/xxx/xxx.php 在第 237 行"

require_once 'dbconfig.php';

$conn = new mysqli("xxxx", "xxxx", $password, $dbname);//host, user, password, database

$result = $conn->query('SELECT * FROM reports') or die(mysqli_error());

//these two lines are the lines 232 and 233
header('Content-Type: text/csv'); // tell the browser to treat file as CSV
header('Content-Disposition: attachment;filename=report.csv'); // tell browser to download a file in user's system with name export.csv

$row = mysqli_fetch_assoc($result); // Get the column names
if ($row) {
    outputcsv(array_keys($row)); // It wil pass column names to outputcsv function
}

//this line here is 237
while ($row) {
    outputcsv($row);    // loop is used to fetch all the rows from table and pass them to outputcsv func
    $row = mysqli_fetch_assoc($result);
 }

 function outputcsv($fields) {
   $csv = '';
    foreach ($fields as $field) {
        $csv .= '"' . $field . '",';
    }
    $csv .= "\r\n";     //Give a carriage return and new line space after each record
    echo $csv;
}

Answer 1

你需要在配置文件中设置输出缓冲区

或

只需在第一行代码写 ob_start() ..

我还建议以 xls 格式导出以获得更好的兼容性。

Answer 2

您需要查找php output buffering。

您在第 183 行 headers already sent by (output started at /xx/xxx/xxx.php:183) 上回显或发送某种数据，然后修改标题。您可以使用 OB 来缓冲要发送到浏览器的信息，修改标头，然后刷新缓冲区。

ob_start();
require_once 'dbconfig.php';

$conn = new mysqli("xxxx", "xxxx", $password, $dbname);//host, user, password, database

$result = $conn->query('SELECT * FROM reports') or die(mysqli_error());

//these two lines are the lines 232 and 233
header('Content-Type: text/csv'); // tell the browser to treat file as CSV
header('Content-Disposition: attachment;filename=report.csv'); // tell browser to download a file in user's system with name export.csv

$row = mysqli_fetch_assoc($result); // Get the column names
if ($row) {
    outputcsv(array_keys($row)); // It wil pass column names to outputcsv function
}

//this line here is 237
while ($row) {
    outputcsv($row);    // loop is used to fetch all the rows from table and pass them to outputcsv func
    $row = mysqli_fetch_assoc($result);
 }

 function outputcsv($fields) {
   $csv = '';
    foreach ($fields as $field) {
        $csv .= '"' . $field . '",';
    }
    $csv .= "\r\n";     //Give a carriage return and new line space after each record
    echo $csv;
}
ob_flush();

您也可以使用ob_get_flush() 或ob_get_contents() 将缓冲区的内容返回为字符串，从而允许从函数等中返回。注意：ob_get_contents() 不会清除缓冲区，它只是返回内容点。

我还看到关于未定义 outputcsv($fields) 的错误，但在解释器可以解决标头问题后，这可能会清除。