Question

问题

所以，我有这个程序，允许用户编辑数据库中的学生信息。当单击提交按钮时，信息将进入数组，因此我可以轻松地遍历信息并将信息放入数据库。但是，问题是我不知道如何确定信息进入哪一列。

我当前的方法是使用变量来跟踪信息应该进入的列，但这不起作用。

我是我的HTML，我将学生信息放入输入中，因此用户可以编辑信息。

学生表

studentID | firstname | lastname | teacherID
1         | Bob       | Roberts  | 2
2         | Rick      | Phil     | 1

PHP表格

<form action="server/edit/students.php" method="post">
                <table>
                    <tr>
                        <th>Student ID</th>
                        <th>Firstname</th>
                        <th>Lastname</th>
                        <th>Teacher ID</th>
                    </tr>
                    <?php
                    // get student info
                    $getStudent = $link->prepare("SELECT * FROM students");
                    $getStudent->execute();
                    $getStudent = $getStudent->fetchAll(PDO::FETCH_ASSOC);
                    $value = 0; // counts rows
                    // loop through each student
                    foreach ($getStudent as $student) {
                        $studentID = $student['studentID'];
                        $firstname = $student['firstname'];
                        $lastname = $student['lastname'];
                        $teacherID = $student['teacherID'];

                     ?>

                        <tr>
                            <td>
                                <?php echo $studentID ?>
                            </td>
                            <td>
                                <input type='text' name='student[<?php echo $studentID ?>][firstname]' value='<?php echo $firstname ?>' />
                            </td>
                            <td>
                                <input type='text' name='student[<?php echo $studentID ?>][lastname]' value='<?php echo $lastname ?>' />
                            </td>
                            <td>
                                <input type='text' name='student[<?php echo $studentID ?>][teacherID]' value='<?php echo $teacherID ?>' />
                            </td>
                        </tr>

                        <?php
                            // add to row
                            $value += 1;

                    }
                    ?>
                </table>
                <button type="submit" name="update">Update</button>
            </form>

PHP代码进程的表单信息

$counter = 0; // keeps track of number of columns

// get data and loop through it
foreach ($_POST['student'] as $id => $data) {
    foreach ($data as $d) {
        if($counter > 1) {
            $counter = 0;

            update($counter, $link, $id, $d);
        } else {
            update($counter, $link, $id, $d);
        }
    }
}

function update($counter, $link, $id, $d) {

    if($counter == 0) {
        $update = $link->prepare("UPDATE students SET firstname = :firstname WHERE studentID = :id");
        $update->execute(array(
            "firstname" => $d,
            "id" => $id
        ));

        echo $counter . "<br>";

        $counter++;
    } else if($counter == 1) {
        $update = $link->prepare("UPDATE students SET lastname = :lastname WHERE studentID = :id");
        $update->execute(array(
            "lastname" => $d,
            "id" => $id
        ));

        echo $counter . "<br>";

        $counter++;
    }

}

Answer 1

问题是因为您的$ counter变量未作为引用传递。请尝试以下方法：

function update(&$counter, $link, $id, $d) {

之前，传递的变量总是等于0.当你递增它时，不会保存更改。使用＆amp;参考时通过引用传递它会告诉PHP更新您最初发送的变量而不是新副本。

编辑：谢谢鲍勃！

跟踪哪些列数据应该进入

1 个答案: