Question

我正在尝试设置2个下拉菜单，一个用于＆＃34;课程＆＃34;以及其他相关的＆＃34;模块＆＃34;选择了课程。

现在＆＃34;课程＆＃34;下拉菜单工作正常。问题是＆＃34;模块＆＃34;下拉式菜单。如果我选择＆＃34;课程＆＃34;下拉菜单，然后它应该在＆＃34;模块＆＃34;中显示与所选课程相关的模块。下拉式菜单。但相反，它只显示＆＃34;请选择＆＃34; ＆＃34;模块＆＃34;的选项下拉菜单，没别的。

如何让相关模块出现在＆＃34;模块＆＃34;下拉菜单？

以下是显示＆＃34;课程＆＃34;的代码。下拉菜单和设置＆＃34;模块＆＃34;下拉菜单，它包含一个jquery，它链接到＆＃34; module.php＆＃34;它将找到的文件，并将相关模块列为＆＃34;模块＆＃34;中的选项。下拉菜单。

<?php

// connect to the database
include('connect.php');

/* check connection */
if (mysqli_connect_errno()) {
printf("Connect failed: %s\n", mysqli_connect_error());
die();
}

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

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

$sqlstmt->execute(); 

$sqlstmt->bind_result($dbCourseId, $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()) 
{ 
$course = $dbCourseId;
$coursename = $dbCourseName; 
$courseHTML .= "<option value='".$course."'>" . $course . " - " . $coursename . "</option>".PHP_EOL;  
} 

$courseHTML .= '</select>'; 
$courseHTML .= '</form>'; 

$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>

以下是module.php页面：

<?php

     // connect to the database
 include('connect.php');

 /* check connection */
 if (mysqli_connect_errno()) {
printf("Connect failed: %s\n", mysqli_connect_error());
die();
}


$course = isset($_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.CourseName, m.ModuleId
"; 

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

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

 $sqlstmt->execute(); 

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


$moduleHTML  = "";  

 while($sqlstmt->fetch()) { 
    $moduleHTML .= "<option value='$dbModuleId'>" . $dbModuleId . "</option>".PHP_EOL;   
} 


echo $moduleHTML; 

 $sqlstmt->execute(); 


?>

Answer 1

将模块放入div并绘制SELECT标签

最好把它全部作为jquery“加载”

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

和

$moduleHTML .= "<select >";
 while($sqlstmt->fetch()) { 
    $moduleHTML .= "<option value='$dbModuleId'>" . $dbModuleId . "</option>".PHP_EOL;   
} 
$moduleHTML .= "</select>";

它不会在下拉菜单中显示相关模块

1 个答案: