更改代碼會導致下拉菜單中的選項不出現

Question

好的，如果您查看editsessionteacher.php腳本，它包含下面的代碼，該代碼在下拉菜單中顯示下面的值時工作：

$outputmodule = ""; 

     $moduleInfo = explode("_", $_POST['modules']); 
     $moduleId = $moduleInfo[0]; 
     $moduleName = $moduleInfo[1]; 
     $outputmodule = sprintf("<p><strong>Module:</strong> %s - %s</p>", $moduleId, $moduleName); 

的module.php是這樣的：

$course = isset($_POST['course']) ? $_POST['course'] : ''; 

$sql = " 
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.CourseId, m.ModuleId 
"; 

$sqlstmt=$mysqli->prepare($sql); 

$sqlstmt->bind_param("s",$course); 

$sqlstmt->execute(); 

$sqlstmt->bind_result($dbCourseId,$dbModuleId,$dbCourseName,$dbModuleName); 


$moduleHTML = ""; 

    while($sqlstmt->fetch()) { 
     $moduleHTML .= sprintf('<option value="%1$s_%2$s">%1$s - %2$s</option>'.PHP_EOL, $dbModuleId, $dbModuleName); 
    } 


echo $moduleHTML; 

$sqlstmt->execute(); 

編輯：

但我想給moduleNo加入到下拉菜單，所以當我試圖修改代碼，這在下面，這是行不通的：

editsessionteacher.php：

 $sql = "SELECT CourseId, CourseNo, CourseName FROM Course"; 

$sqlstmt=$mysqli->prepare($sql); 

$sqlstmt->execute(); 

$sqlstmt->bind_result($dbCourseId, $dbCourseNo, $dbCourseName); 

$courses = array(); // easier if you don't use generic names for data 

$courseHTML = ""; 
$courseHTML .= '<select name="courses" id="coursesDrop" onchange="getModules();">'.PHP_EOL; 
$courseHTML .= '<option value="">Please Select</option>'.PHP_EOL; 

while($sqlstmt->fetch()) 
{ 
    $courseno = $dbCourseNo; 
    $course = $dbCourseId; 
    $coursename = $dbCourseName; 
    $courseHTML .= "<option value='".$course."'>" . $courseno . " - " . $coursename . "</option>".PHP_EOL; 
    } 

    $courseHTML .= '</select>'; 

    $moduleHTML = ""; 
    $moduleHTML .= '<select name="modules" id="modulesDrop">'.PHP_EOL; 
    $moduleHTML .= '<option value="">Please Select</option>'.PHP_EOL; 
    $moduleHTML .= '</select>'; 


    ?> 

    <script type="text/javascript"> 

    function getModules() { 
    var course = jQuery("#coursesDrop").val(); 
    jQuery('#modulesDrop').empty(); 
    jQuery('#modulesDrop').html('<option value="">Please Select</option>'); 
    jQuery.ajax({ 
    type: "post", 
    url: "module.php", 
    data: { course:course }, 
    success: function(response){ 
    jQuery('#modulesDrop').append(response); 
    } 
    }); 


    } 


    </script> 


<form action="<?php echo htmlentities($_SERVER['PHP_SELF']); ?>" method="post" onsubmit="return validation();"> 
<table> 
<tr> 
<th>Course: <?php echo $courseHTML; ?></th> 
<th>Module: <?php echo $moduleHTML; ?></th> 
</tr> 
</table> 
<p><input id="moduleSubmit" type="submit" value="Submit Course and Module" name="moduleSubmit" /></p> 
</form> 

<?php 

if (isset($_POST['moduleSubmit'])) {  

$outputmodule = ""; 

$moduleInfo = explode("_", $_POST['modules']); 
$moduleId = $moduleInfo[0]; 
$moduleNo = $moduleInfo[1]; 
$moduleName = $moduleInfo[2]; 
$outputmodule = sprintf("<p><strong>Module:</strong> %s - %s</p>", $moduleNo, $moduleName); 


.... 

module.php：

$course = isset($_POST['course']) ? $_POST['course'] : ''; 

    $sql = " 
    SELECT cm.CourseId, cm.ModuleId, c.CourseNo, m.ModuleNo, 
    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.CourseId, m.ModuleId 
    "; 

    $sqlstmt=$mysqli->prepare($sql); 

    $sqlstmt->bind_param("s",$course); 

    $sqlstmt->execute(); 

    $sqlstmt->bind_result($dbCourseId,$dbModuleId,$dbCourseNo,$dbModuleNo,$dbCourseName,$dbModuleName); 


    $moduleHTML = ""; 

$moduleHTML .= '<select name="modules" id="modulesDrop">'.PHP_EOL; 
$moduleHTML .= '<option value="">Please Select</option>'.PHP_EOL; 

while($sqlstmt->fetch()) { 
    $moduleHTML .= sprintf('<option value="%1$s">%2$s - %3$s</option>'.PHP_EOL, $dbModuleId, $dbModuleNo, $dbModuleName); 
} 

$moduleHTML .= '</select>'; 

echo $moduleHTML; 

我的問題這就是爲什麼當我改變代碼來添加模塊號時，它不會在下拉菜單中顯示任何內容。

Answer 1

我不明白爲什麼你的下拉菜單不顯示，但我確實看到一個問題，你修改後的module.phpsprintf()以及它將如何顯示在你的editsessionteacher.php中。

-

原來module.phpsprintf()通過2個值用 '_'

$moduleHTML .= sprintf('<option value="%1$s_%2$s">%1$s - %2$s</option>'.PHP_EOL, $dbModuleId, $dbModuleName); 
             --------- 

和你editsessionteacher.phpexplode()的2個值

$moduleInfo = explode("_", $_POST['modules']); 
$moduleId = $moduleInfo[0]; 
$moduleName = $moduleInfo[1]; 

，但修改後的module.phpsprintf()只有在通過1個值鏈接

$moduleHTML .= sprintf('<option value="%1$s">%2$s - %3$s</option>'.PHP_EOL, $dbModuleId, $dbModuleNo, $dbModuleName); 
             ----- 

但你editsessionteacher.php試圖explode() 3個值

$moduleInfo = explode("_", $_POST['modules']); 
$moduleId = $moduleInfo[0]; 
$moduleNo = $moduleInfo[1]; 
$moduleName = $moduleInfo[2]; 

因此，基於把你editsessionteacher.phpexplode()，嘗試更新module.phpsprintf()到 -

$moduleHTML .= sprintf('<option value="%1$s_%2$s_%3$s">%2$s - %3$s</option>'.PHP_EOL, $dbModuleId, $dbModuleNo, $dbModuleName); 
             --------------