如何从相同的输入名称保存多个值

时间:2019-04-07 01:24:46

标签: php sql forms mysqli

如何从相同的输入名称中保存多行值。

例如,我的php,html代码来自:

<form action="functions.php" method="post" name="grades">
    <table>
        <thead>
            <tr>
                <th>Subject</th>
                <th>Grade</th>
            </tr>
        </thead>
        <tbody>
            <?php $unos = $baza->odradi("SELECT subject FROM subjects ORDER BY id ASC"); 
            if (!empty($unos)) { 
                foreach($unos as $row=>$value){ ?>
                    <tr>
                        <td><input type="hidden" name="subject_id[]" value="<?= $unos[$row]["id"]; ?>"> <?= $unos[$row]["subject"]; ?></td>
                        <td>
                            <select class="form-control input-xs" name="grade_id[]" required>
                                <option selected disabled>Select grade</option>
                                <option value="5">excelent</option>
                                <option value="4">very good</option>
                                <option value="3">good</option>
                                <option value="2">ok</option>
                                <option value="1">bad</option>
                            </select>
                        </td>
                    </tr>
        </tbody>
    </table>
    <input type="submit" name="grades" class="btn btn-success btn-lg" value="Submit grades">
</form>

需要保存的函数如下所示:

if (isset($_POST['grades'])) {  
    foreach (array_combine($_POST['subject_id'], $_POST['grade_id']) as $i => $val){
        $subject = $_POST["subject_id"][$i];
        $grade = $_POST["grade_id"][$i];

        $sql = "INSERT INTO final_grade (subject_id,grade_id) VALUES ('$subject','$grade')";
        $u = mysqli_query($db, $sql);
    }

但是一切都搞砸了,在前两行中没有保存成绩或主题,并且所有的行都完全丢失了。

1 个答案:

答案 0 :(得分:0)

因为您正在调用array_combine(),所以循环不再像$i那样传递子数组索引。它以subject_id的形式传递$i,以grade_id的形式传递$val。您可能只是使用$i$val作为要插入的值,而不是尝试使用$_POST重新访问$i数组。

更干净的脚本编写方法是将id用作每个<select>上的硬编码元素键,而不是传递隐藏字段。

<?php
$options = [
    5 => 'excellent',
    4 => 'very good',
    3 => 'good',
    2 => 'ok',
    1 => 'bad'
];
?>

<td><?= $unos[$row]["subject"]; ?></td>
<td><select class="form-control input-xs" name="grade[<?= $unos[$row]["id"]; ?>]" required>
    <option disabled>Select grade</option>
    <?php
    foreach ($options as $opt_id => $opt_val) {
        echo "<option value=\"{$opt_id}\">{$opt_val}</option>";
    }
    ?>
    </select>
 </td>

然后,您可以简单地访问关联的提交。

if (isset($_POST['grade'])) {  
    // use prepared statement and bind variables
    foreach ($_POST['grade'] as $id => $val) {
        // execute prepared statement with each iteration
    }
}

或者,您可以建立单批结果并执行一次INSERT(我可能会这样做)。

未经测试的建议:

$data = [];
foreach ($_POST['grade'] as $subject_id => $grade_id) {
    array_push($data, $subject_id, $grade_id);  // restructure as indexed 1-dim array for unpacking
}
$num_of_inserts = sizeof($data);
$placeholders = array_fill(0, $num_of_inserts, '(?,?)');
$value_types = str_repeat('i', $num_of_inserts * 2);  // i is because you are passing integer values

// execute single batch of inserts
$query = "INSERT INTO final_grade (subject_id,grade_id) VALUES " . implode(',', $placeholders);
$stmt = $conn->prepare($query); 
$stmt->bind_param($value_types, ...$data);
$stmt->execute();

事实是,您可以通过多种方式传递表单数据,也可以通过多种方式执行INSERT查询。我不会费心写出所有变体-做您喜欢的事...但是绝对要写稳定/安全的查询。