提交后，如何将Echo和Drop Dowm菜单保留在页面上

Question

在我的主要应用程序中，我希望以下布局出现：

1. 打开应用程序时，它将显示"课程"文本输入和提交按钮以提交课程。（正常工作）

2. 当用户进入课程并提交（成功）时，它将在回声中显示下面的课程的名称和ID按钮提交模块。（这很好）

3. 当用户提交模块时，以下应发生：

应该保留课程名称的回声（暂时消失在用户提交模块

之后

提交模块后，模块下拉菜单应保留在页面上（暂时消失了

从下拉菜单中提交模块时，我该如何获得上述项目符号。

<?php
     // connect to the database
 include('connect.php');
 /* check connection */
 if (mysqli_connect_errno()) {
printf("Connect failed: %sn", mysqli_connect_error());
die();
}
 $courseid = (isset($_POST['courseid'])) ? $_POST['courseid'] : '';
?>
   <h1>DELETING AN ASSESSMENT</h1>
    <form action="<?php echo htmlentities($_SERVER['PHP_SELF']); ?>" method="post">
     <p>Course ID: <input type="text" name="courseid" /><input id="courseSubmit" type="submit" value="Submit" name="submit" /></p>      
    </form>

    <?php
  if (isset($_POST['submit'])) {
    $query = "
             SELECT cm.CourseId, cm.ModuleId, 
             c.CourseName,
             m.ModuleName
             FROM Course c
             INNER JOIN Course_Module cm ON c.CourseId = cm.CourseId
             JOIN Module m ON cm.ModuleId = m.ModuleId
             WHERE
             (c.CourseId = ?)
             ORDER BY c.CourseName, m.ModuleId
            ";
$qrystmt=$mysqli->prepare($query);
// You only need to call bind_param once
$qrystmt->bind_param("s",$courseid);
// get result and assign variables (prefix with db)
$qrystmt->execute(); 
$qrystmt->bind_result($dbCourseId,$dbModuleId,$dbCourseName,$dbModuleName);
 $qrystmt->store_result();
$num = $qrystmt->num_rows();
if($num ==0){
    echo "<p>Sorry, No Course was found with this Course ID '$courseid'</p>";
} else { 
    $dataArray = array();
 while ( $qrystmt->fetch() ) { 
      // data array
      $dataArray[$dbCourseId]['CourseName'] = $dbCourseName; 
      $dataArray[$dbCourseId]['Modules'][$dbModuleId]['ModuleName'] = $dbModuleName; 
       // session data
      $_SESSION['idcourse'] = $dbCourseId;
      $_SESSION['namecourse'] = $dbCourseName;
}
 foreach ($dataArray as $courseId => $courseData) {
      $output = ""; 
      $output .= "<p><strong>Course:</strong> " . $courseId .  " - "  . $courseData['CourseName'] . "</p>";
   $moduleHTML = ""; 
   $moduleHTML .= '<select name="modulesDrop" id="modulesDrop">'.PHP_EOL;
   $moduleHTML .= '<option value="">Please Select</option>'.PHP_EOL;      
        foreach ($courseData['Modules'] as $moduleId => $moduleData) {        
        $moduleHTML .= "<option value='$moduleId'>" . $moduleId . " - " .   
    $moduleData['ModuleName'] ."</option>".PHP_EOL;        
  } 
        }
        $moduleHTML .= '</select>';
  echo $output;

    ?>
     <form action="<?php echo htmlentities($_SERVER['PHP_SELF']); ?>" method="post">
     <p>Module: <?php echo $moduleHTML; ?><input id="moduleSubmit" type="submit" value="Submit" name="modulesubmit" /></p>      
    </form> 

    <?php
}
}
 if (isset($_POST['modulesubmit'])) {
 var_dump($_POST['modulesDrop']);
        $sessionquery = "
             SELECT SessionId, SessionDate, SessionTime, ModuleId
             FROM Session
             WHERE
             (ModuleId = ?)
             ORDER BY SessionDate, SessionTime 
            ";
$sessionqrystmt=$mysqli->prepare($sessionquery);
// You only need to call bind_param once
$sessionqrystmt->bind_param("s",$_POST['modulesDrop']);
// get result and assign variables (prefix with db)
$sessionqrystmt->execute(); 
$sessionqrystmt->bind_result($dbSessionId,$dbSessionDate,$dbSessionTime, $dbModuleId);
 $sessionqrystmt->store_result();
$sessionnum = $sessionqrystmt->num_rows();   
    $dataArraySession = array();
 while ( $sessionqrystmt->fetch() ) { 
 $dataArraySession[$dbSessionId]['SessionDate'] = $dbSessionDate; 
 $dataArraySession[$dbSessionId]['SessionTime'] = $dbSessionTime;
}
foreach ($dataArraySession as $sessionId => $sessionData) {

   $sessionHTML = ""; 
   $sessionHTML .= '<select name="session" id="sessionsDrop">'.PHP_EOL;
   $sessionHTML .= '<option value="">Please Select</option>'.PHP_EOL;           
   $sessionHTML .= "<option value='$sessionId'>" . $sessionId . " - " . $sessionData['SessionDate']. " - " . $sessionData['SessionTime'] ."</option>".PHP_EOL;        
   $sessionHTML .= '</select>';
        }

 if ($sessionnum > 0) {
 ?>
     <form action="<?php echo htmlentities($_SERVER['PHP_SELF']); ?>" method="post">
     <p>Sessions: <?php echo $sessionHTML; ?><input id="sessionSubmit" type="submit" value="Submit" name="sesionsubmit" /></p>      
    </form>       
<?php
}
else {
 echo "<p>Sorry, You have No Sessions under this Module</p>";
}

}

    ?>

Answer 1

您的代码有几个问题。您遇到的问题是，您没有从第1阶段到第3阶段传递信息" $ courseid"。要这样做，只需将以下内容添加到阶段2

<input type="hidden" name="courseid" value="<?=$courseid?>" />