如何根据下拉选择框中的选择更新 sql 数据库中的特定记录？

Question

好的，我在这上面花了几天时间，但我已经超出了我的深度。我承认我对 sql、jquery 和 ajax 完全陌生。我为此提前道歉。

我正在尝试构建一个应用程序，管理员可以在其中查看用户一段时间内的表现，平均过去 2 周的输入分数。使用下拉框应该从数据库中选择一个成员（这部分似乎有效），然后可以填写下面的表格并按下“更新”按钮来更新数据库中的记录（这完全被破坏了）。

选择框是使用 ajax 从数据库中填充的，我可以使用 onchange 函数从选择中返回值，但是当我尝试使用我的表单更新数据库时，什么都没有更新。

插入按钮和相关代码正常工作，信息正确存储在数据库中。 （当我的代码正确时，我会将数据分成更准确的表格，因为我不想在挣扎时处理联接和多个表格。）

从选择菜单中选择名称时，$_POST['memberID'] 会显示正确的数字。

在表单中输入信息并按下“更新”后，$_POST['memberID'] 为空白且数据库不会更新。

Controller.php：

<?php require 'php/dbconnect.php';
$records = array();
if(!empty($_POST)) {
    switch (true) {
        case isset($_POST['insert']):
            if(isset($_POST['name'], $_POST['designation'], $_POST['rank'], $_POST['currentScore'])) {
                // The following trim functions followed by !empty ensures that a series of spaces is not accepted from users as input.
                $name = trim($_POST['name']);
                $designation = trim($_POST['designation']);
                $rank = trim($_POST['rank']);
                $currentScore = trim($_POST['currentScore']);

                if(!empty($name) && !empty($designation) && !empty($rank) && !empty($currentScore)) {

                    $insert = $conn->prepare("INSERT INTO members (name, designation, rank, currentScore) VALUES (?,?,?,?)");
                    $insert->bind_param('ssii' , $name, $designation, $rank, $currentScore);

                    if($insert->execute()) {
                        $insert->free(); //Remove Query Data from memory since it is no longer needed.
                        header('location: index.php');
                        die();
                    }
                }
            }
        break;

        case isset($_POST['update']):
            $name = trim($_POST['name']);
            if(!empty($name)) {
            $update = $conn->prepare("UPDATE members SET name = ? WHERE '$memberID'");
            $update->bind_param('s', $name);
                if($update->execute()) {
                        header('location: index.php');
                        die();
                    }
            }
        break;

//      case isset($_POST['delete']):
//          // Delete statement goes here
//      break;
//      else 
    }
}
if($results = $conn->query("SELECT *, ((previousScore + currentScore) / 2) AS avgScore FROM members")) {
    if($results->num_rows) {
        while($row = $results->fetch_object()) {
            $records[] = $row; //Appending value to array
        }
        $results->free();
    }
}
?>

索引.php：

<?php include 'header.php' ?>
     <?php if(!count($records)) {
        echo 'No Records' ;
     } else {
     ?>
    <form id="memberSelect" method="post">
        <select name="memberID" id="members" onchange="change()">
            <!-- Populated with function members in footer.php -->
        </select>
    </form>
        <table>
            <thead>
                <tr>
                    <th>Name</th>
                    <th>Designation</th>
                    <th>Rank</th>
                    <th>Previous Score</th>
                    <th>Current Score</th>
                    <th>Average Score</th>
                </tr>
            </thead>
            <tbody>
                <?php
                foreach($records as $r) {
                ?>

                <tr>
                    <td><?php echo escape($r->name); ?></td>
                    <td><?php echo escape($r->designation); ?></td>
                    <td><?php echo escape($r->rank); ?></td>
                    <td><?php echo escape($r->previousScore); ?></td>
                    <td><?php echo escape($r->currentScore); ?></td>
                    <td><?php echo escape($r->avgScore); ?></td>
                    <!-- Remember when putting data in that current score needs to be moved to previous score's
                    position and the NEW score will take the place of current score(which will be the old score until updated) -->
                </tr>
                <?php 
                }
                ?>
            </tbody>
        </table>
    <?php
    }
    ?>

    <hr>

    <form action="" method="post">
        <div class="field">
            <label for="name">Member name</label>
            <input type="text" name="name" id="name" autocomplete="off">
        </div>
        <div class="field">
            <label for="designation">Designation</label>
            <input type="text" name="designation" id="designation" autocomplete="off">
        </div>
        <div class="field">
            <label for="rank">Rank</label>
            <input type="text" name="rank" id="charLevel" autocomplete="off">
        </div>
        <div class="field">
            <label for="currentScore">Current Score</label>
            <input type="text" name="currentScore" id="currentScore" autocomplete="off">
        </div>
        <div id="submit">
            <!-- Add a comment section to be input into DB -->
            <input type="submit" name="insert" value="Insert">
            <input type="submit" name="update" value="Update">
            <input type="submit" name="delete" value="Delete">
            <!-- <input type="hidden" name="id" value="<?php //echo $?>"> -->
        </div>
    </form>
<?php include 'footer.php' ?>

页脚.php：

</div>

        <script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.3/jquery.min.js"></script>
        <script>window.jQuery || document.write('<script src="js/vendor/jquery-1.11.3.min.js"><\/script>')</script>
        <script src="js/plugins.js"></script>
        <script src="js/main.js"></script>
        <script>
            //How do you explain something you barely understand? The following function uses JQUERY
            //json, and ajax to fill a select dropdown with items populated from a linked database.
            //See the jsonData.php for the json data being referenced here, it is imperitive to the operation of
            //this function that json data be available.
            function members(){
                $('#members').empty();//Removes all content of the associated ID 'members' to ensure a clean default value
                $('#members').append("<option>Loading</option>");//fill them with a default message
                $.ajax({
                    type:"POST",
                    url:"php/jsonData.php",//the location of the json data, for this it is required to be in its own file
                    contentType:"application/json; charset=utf-8",
                    dataType: "json",
                    success: function(records){ //only fires if the json data is found
                        $('#members').empty();//If everything is ok, removes previous default value
                        $('#members').append("<option value='0'>--Select Member--</option>");
                        $.each(records,function(i,memberID){//Uses a foreach loop to fire a function for every memberID, assigning the value to i
                            $('#members').append('<option value="'+ records[i].memberID +'">'+ records[i].name +'</option>');
                            //^ The workhorse. Grabs the select value by the ID, appends the option value by looking within the records array
                            //(which is defined and assigned values in the jsonData.php file) and assigns the member id as the value and the 'name'
                            //as the option. This populates the dropdown with the names and gives them the value 'memberID' from the database.
                        });
                    },
                    complete: function(){
                     }
                });
            }
            $(document).ready(function(){
                members();
            });
        </script>
        <script>
            function change(){
                $('#memberSelect').submit();//Submits the page to the server when called
            }
        </script>

        <!-- Google Analytics: change UA-XXXXX-X to be your site's ID. -->
        <script>
            (function(b,o,i,l,e,r){b.GoogleAnalyticsObject=l;b[l]||(b[l]=
            function(){(b[l].q=b[l].q||[]).push(arguments)});b[l].l=+new Date;
            e=o.createElement(i);r=o.getElementsByTagName(i)[0];
            e.src='https://www.google-analytics.com/analytics.js';
            r.parentNode.insertBefore(e,r)}(window,document,'script','ga'));
            ga('create','UA-XXXXX-X','auto');ga('send','pageview');
        </script>
    </body>
</html>

Answer 1

我认为问题出在更新块的这一行：

$update = $conn->prepare("UPDATE members SET name = ? WHERE '$memberID'");

我假设您的成员表的主键是：member_id

那么这段代码将是：

$update = $conn->prepare("UPDATE members SET name = ? WHERE member_id = ?");
$update->bind_param('si', $name, $memberID);

试试这个。希望对您有所帮助。