Question

从下拉菜单中进行选择后，我试图立即提交表单。提交表单后，我想基于下拉菜单中的选择向MySQL数据库发送查询，并显示检索到的文本。

目前，对于我下面的内容，没有任何显示，不会引发任何错误。 JS提交事件处理程序可以工作，但是在页面重新加载后，不会显示新文本。

非常感谢您的帮助。

提交表单的JS：

// Set all fetch requests as an object by default
$dbo->setAttribute(PDO::ATTR_DEFAULT_FETCH_MODE, PDO::FETCH_OBJ);

$admin = 'ADMIN';
$adminLive = 'ADMIN-live';
$adminType = 'ADMIN_US_Type';
$customusDomestic = 'US_domestic';
$adminChina = 'China_admin';
$adminIndia = 'India_admin';
$adminCustom = 'ADMIN_custom';
$customusaustinCulver = 'US_Austin_Culver';
$customuschinaTokyo = 'US_China_Tokyo';
$customcorkuaeBayarea = 'Cork_UAE_BayArea';
$customchinashanghaiBeijing = 'China_Shanghai_Beijing';
$adminselfMoves = 'ADMIN_selfmoves';
$adminmilanVienna = 'ADMIN-milan-vienna';
$custombayareaSeattle = 'Bayarea_Seattle_admin';

// Prepare the query
$sql = 'SELECT DISTINCT usergroup
        FROM plus_signup
        WHERE usergroup != ?
        AND usergroup != ?
        AND usergroup != ?
        AND usergroup != ?
        AND usergroup != ?
        AND usergroup != ?
        AND usergroup != ?
        AND usergroup != ?
        AND usergroup != ?
        AND usergroup != ?
        AND usergroup != ?
        AND usergroup != ?
        AND usergroup != ?
        AND usergroup != ?';

$stmt = $dbo->prepare($sql);

// Execute the query
$stmt->execute([$admin,$adminLive,$adminType,$customusDomestic,$adminChina,$adminIndia,$adminCustom,$customusaustinCulver,$customuschinaTokyo,$customcorkuaeBayarea,$customchinashanghaiBeijing,$adminselfMoves,$adminmilanVienna,$custombayareaSeattle]);

$usergroups = $stmt->fetchAll();
foreach($usergroups as $locations) {

     // This works fine but my output is adding an extra br in some occurances of the loop
    echo $locations->usergroup . "<br/>";

}

提交表单后运行的PHP：

$(".platformSelectDropDown").change(function() {
  $('.platformSelectForm').submit();
});

用于查询和返回数据的PHP函数：

if($_SERVER['REQUEST_METHOD'] == 'POST') {
  $platform = $_POST['platformSelectDropDown'];
  $description = call_data($tableName, $platform)['Description'];
  $application = call_data($tableName, $platform)['Application'];
}

表格：

function call_data($tableName, $col, $platformName) {
  include('connection.php');
  $sql = 'SELECT * FROM $tableName WHERE platform_name = $platformName';
  try {
    return $db->query($sql);
  }
  catch (Exception $e) {
    echo "Error! " . $e->getMessage() . "<br/>";
    return array();
  }
}

Answer 1

我相信下面的代码可以实现您想要的功能，并且在安全性和功能上有所改进。但是，请注意，从您的代码来看，尚不清楚设置$tableName的位置，因此我只是将其硬编码为测试表。我将php和html混合在一起，因为它使我更容易解决问题，并且我认为它将使您更容易遵循我的解决方案。如果您愿意，没有理由可以将其拆分回去并实现php部分的功能，类似于您的原始方法。检查一下：

<html>
    <body>
        <form class="platformSelectForm" id="platformSelectForm" method="post">

                <?php

                    // Get which dropdown option is selected, if any, so can keep selected on page reload 
                    if(!isset($_POST['platformSelectDropDown'])) {

                        // Not postback, default to first option ("Select One")
                        $p0Select = ' selected';
                        $p1Select = '';
                        $p2Select = '';

                    } else {

                        // Is postback
                        // Set variables for query below
                        $tableName = 'tbl_platforms_1';
                        $platformName = $_POST['platformSelectDropDown'];

                        // set dropdown selection to whatever was select at form submission 
                        if($platformName == 'Platform_1') {
                            $p1Select = ' selected';
                        } elseif ($platformName == 'Platform_2') {
                            $p2Select = ' selected';
                        } else {
                            $p0select = ' selected';
                        }
                    }

                    ?>

                    <select name="platformSelectDropDown" class="platformSelectDropDown" onchange="document.getElementById('platformSelectForm').submit()">
                        <option value="Select_One"<?php echo $p0Select; ?>>Select One</option>
                        <option value="Platform_1"<?php echo $p1Select; ?>>Platform 1</option>
                        <option value="Platform_2"<?php echo $p2Select; ?>>Platform 2</option>
                    </select>


                    <?php

                        // If dropdown value is set and does not equal "Select_One"
                        if(isset($_POST['platformSelectDropDown'])&& $_POST['platformSelectDropDown'] != 'Select_One') {

                            ?>
                            <ul class="indent">
                            <?php

                                try {

                                    // Set database parameters 
                                    // Replace these values with appropriate values for your database
                                    // (okay to use an include like you did originally)
                                    $dbhost = 'your_database_host';
                                    $dbname = 'your_database_name';
                                    $dbuser = 'your_database_user';
                                    $dbpass = 'your_database_user_password';

                                    // Create PDO
                                    $conn = new PDO("mysql:host=$dbhost;dbname=$dbname", $dbuser, $dbpass);
                                    $conn->setAttribute(PDO::ATTR_EMULATE_PREPARES, false);
                                    $conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);

                                    // Prepare SQL statement and bind parameters
                                    $stmt = $conn->prepare("SELECT * FROM $tableName WHERE platform_name = :platformName");
                                    $stmt->bindValue(':platformName', $platformName, PDO::PARAM_STR);

                                    // Execute statement and return results in an associative array (e.g., field_name -> value)
                                    $stmt->execute();
                                    $results = $stmt->fetchAll(PDO::FETCH_ASSOC);

                                    // Close Connection
                                    $conn = null;

                                    // For each row that was returned, output results
                                    for ($i = 0; $i < count($results); $i++) {
                                        echo '<li>' .$results[$i]['Description'] .'</li>';
                                        echo '<li>' .$results[$i]['Application'] .'</li>';
                                    }

                                } catch (Exception $e) {
                                    echo '<li>Error! ' .$e->getMessage() . '</li>';
                                }
                            ?>
                            </ul>
                            <?php
                        };
                ?>
        </form>
    </body>
</html>

我用来设置测试的代码：

DROP TABLE IF EXISTS tbl_platforms_1;
CREATE TABLE IF NOT EXISTS tbl_platforms_1 (
    id int AUTO_INCREMENT NOT NULL,
    platform_name varchar(20),
    Description varchar(20),
    Application varchar(20),
    PRIMARY KEY (id)
);

INSERT INTO 
    tbl_platforms_1
        (platform_name, Description, Application)
    VALUES 
        ('Platform_1', 'Description 1', 'Application 1'),
        ('Platform_2', 'Description 2', 'Application 2');

如果这可以解决您的问题，请记住标记为已回答，这样每个人都将知道您不再需要帮助（因此，我花了很多时间提出此解决方案:-），我将得到奖励。如果这样做不能解决您的问题，请提供尽可能多的详细信息，说明当前结果与您期望的结果有何不同，我将尝试对其进行修改以满足您的需求。谢谢！

查询MySQL数据库，然后在提交表单后显示检索到的文本

1 个答案: