嘗試從下拉菜單中刪除會話時發生未定義索引錯誤

我想從下拉菜單中刪除會話。用戶將從下拉菜單中選擇一個會話，然後點擊刪除按鈕，這應該刪除數據庫中的會話。問題是，如果我點擊刪除按鈕，它會出現一個未定義的索引錯誤，說明sessionsDrop未在200行中定義我的問題是：嘗試從下拉菜單中刪除會話時發生未定義索引錯誤

1：如何擺脫未定義的代碼索引錯誤2：如何以及在哪裏編寫if語句，以便如果刪除成功，則會回顯「Session ... was Deleted」，否則如果未刪除則顯示回顯「發生錯誤，會話。 ..沒有刪除」

下面是代碼：

$sessionnum = 0; 

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

    if($_REQUEST['modulesDrop']==''){ 

     echo "Please Select a Module from the Drop Down Menu Above"; 

    } 
    else{ 

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; 

} 

    $sessionHTML = ""; 
    $sessionHTML .= '<select name="session" id="sessionsDrop">'.PHP_EOL; 
    $sessionHTML .= '<option value="">Please Select</option>'.PHP_EOL;  

foreach ($dataArraySession as $sessionId => $sessionData) { 

    $sessionHTML .= "<option value='$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="Delete" name="sessionsubmit" /></p>  
    </form>  

<?php 

} 
else { 
echo "<p>Sorry, You have No Sessions under this Module</p>"; 
} 

} 

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

    if($_REQUEST['sessionsDrop']==''){ //line 200 where undefined index occurs 

     echo "Please Select a Session from the Drop Down Menu Above to Delete a Session"; 

    } 
    else{ 

var_dump($_POST['sessionsDrop']); 

$sessiondel = $_POST['sessionsDrop']; 

     $sessiondeletesql = " DELETE sess 
     FROM Session AS sess 
     WHERE sess.SessionId = ?"; 


       if (!$delete = $mysqli->prepare($sessiondeletesql)) { 
     // Handle errors with prepare operation here 
    } 

    //Dont pass data directly to bind_param store it in a variable 
$delete->bind_param("s", $sessiondel); 

$delete->execute(); 

     if ($delete->errno) { 
      // Handle query error here 
     } 

     $delete->close(); 

     echo "Session $sessiondel was Deleted"; 
} 
} 
    ?>

來源

2012-10-19 user1723710

你undefined index錯誤是因爲您使用$_REQUEST['sessionsDrop']==''，但你的表單代碼是 -

$sessionHTML .= '<select name="session" id="sessionsDrop">'.PHP_EOL;

所以，你應該用$_REQUEST['session']==''，而不是$_REQUEST['sessionsDrop']==''因爲超級全局（$_POST，$_GET，$_REQUEST）引用name，而不是id。

來源

2012-10-19 05:09:42 Sean

嘗試從下拉菜單中刪除會話時發生未定義索引錯誤

回答

相關問題