Question

我在下面有一个评估下拉菜单：

<select name="session" id="sessionsDrop">
<option value="All">All</option>
<option value="2">EOWOW</option>
<option value="34">EOWOW</option>
</select>  


 <select name="student" id="studentsDrop">
    <option value="All">All</option>
    <option value="23">Jay Hart</option>
    <option value="32">Bubba Wright</option>
    </select>

上面是一个简单的下拉菜单。我在下面运行查询以获取所选学生的详细信息以及获取所选的评估详细信息。现在选定的评估输出细节没有问题，

但是，所选学生选项的回显不起作用，就像用户选择All选项，然后回显"<p><strong>Students: </strong>All Students - Total:(" .$selstudentnum . ")</p>" . PHP_EOL;一样。但问题是如果选择All选项，它不会显示此回显。事实上，如果选择了All选项，它根本不会显示回声。我尝试了===和==，但看不出我做错了什么。任何人都可以看到导致这个问题的原因吗？如果用户选择单个studnet，那么它会显示没有问题的回声。只有在选择了All时才会这样做。

$selectedsessionqry = "
SELECT
SessionName, SessionDate, SessionTime
FROM
Session
WHERE
(SessionId = ?)
";

global $mysqli;
$selectedsessionstmt=$mysqli->prepare($selectedsessionqry);
// You only need to call bind_param once
$selectedsessionstmt->bind_param("i",$_POST["session"]);
// get result and assign variables (prefix with db)
$selectedsessionstmt->execute(); 
$selectedsessionstmt->bind_result($selSessionName,$selSessionDate,$selSessionTime);

 while ($selectedsessionstmt->fetch()) {

     echo "<p><strong>Assessment: </strong>" . $selSessionName . " - " . date('d-m-Y',strtotime($selSessionDate)) . " - " . date('H:i',strtotime($selSessionTime)) . "</p>" . PHP_EOL;

 }


$selectedsessionstmt->close();   

    $selectedstudentqry = "
        SELECT
        StudentAlias, StudentForename, StudentSurname
        FROM
        Student
        WHERE
        (StudentId = ?)
        ";

        global $mysqli;
        $selectedstudentstmt=$mysqli->prepare($selectedstudentqry);
        // You only need to call bind_param once
        $selectedstudentstmt->bind_param("i",$_POST["student"]);
        // get result and assign variables (prefix with db)
        $selectedstudentstmt->execute(); 
        $selectedstudentstmt->bind_result($selStudentAlias,$selStudentForename,$selStudentSurname);
        $selectedstudentstmt->store_result();
        $selstudentnum = $selectedstudentstmt->num_rows();   

         while ($selectedstudentstmt->fetch()) {

        if($_POST["student"] === 'All') {
            echo "<p><strong>Students: </strong>All Students - Total:(" .$selstudentnum . ")</p>" . PHP_EOL;
        }else{
            echo "<p><strong>Students: </strong>" . $selStudentAlias . " - " . $selStudentForename . " " . $selStudentSurname . "</p>" . PHP_EOL;
        }
        }

从下拉菜单中选择“全部”会导致回显不出现

0 个答案: