以下に、モジュールのドロップダウンメニューがあります。ここでは、データベースからモジュールのリストを取得し、ドロップダウンメニューにモジュールを表示します。また、選択したモジュール番号とモジュール名を$output変数と非表示の入力（$hiddenoutput）に表示し、選択したモジュールのモジュールIDを表示します（これは、テキスト入力が非表示に変更される前にテキストであった場合に正常にテキストメッセージが送信されました）
$active = 1;
$sql = "SELECT ModuleId, ModuleNo, ModuleName FROM Module WHERE ModuleActive = ? ORDER BY ModuleNo";
$sqlstmt=$mysqli->prepare($sql);
$sqlstmt->bind_param("i",$active);
$sqlstmt->execute();
$sqlstmt->bind_result($dbModuleId, $dbModuleNo, $dbModuleName);
$modules = array(); // easier if you don't use generic names for data
$output = "";
$hiddenoutput = "";
$moduleHTML = "";
$moduleHTML .= '<select name="module" id="modulesDrop">'.PHP_EOL;
$moduleHTML .= '<option value="">Please Select</option>'.PHP_EOL;
while($sqlstmt->fetch())
{
$moduleno = $dbModuleNo;
$module = $dbModuleId;
$modulename = $dbModuleName;
$moduleHTML .= "<option value='".$module."'>" . $moduleno . " - " . $modulename . "</option>".PHP_EOL;
if (isset($_POST['module']) && ($_POST['module'] == $module)) {
$output .= "<p><strong>Selected Module:</strong> " . $moduleno . " - " . $modulename . "</p>";
$hiddenoutput .= "<p><input type='hidden' id='hiddenoutput' name='hiddenmodule' value='". $module ."'></p>";
}
}
$moduleHTML .= '</select>';
$submittedModuleId = (isset($_POST['module'])) ? $_POST['module'] : '';
$output = (isset($output)) ? $output : '';
$hiddenoutput = (isset($hiddenoutput)) ? $hiddenoutput : '';
詳細は以下のフォームに表示されます。
<form action="<?php echo htmlentities($_SERVER['PHP_SELF']); ?>" method="post">
<table>
<tr>
<th>Module: <?php echo $moduleHTML; ?><input id="moduleSubmit" type="submit" value="Submit" name="submit" /></th>
</tr>
<tr>
<td><span id="errormsg"><?php echo $errormsg; ?></span><?php echo $hiddenoutput . $output; ?></td>
</tr>
</table>
</form>
しかし、私が本当に理解していないのは、以下のINSERT sqlでは、1つを除くすべての値を取得して挿入でき、それが非表示の入力に表示されるモジュールIDの値であるということです。それは述べ続けます：
Warning: mysqli_stmt::execute(): (23000/1048): Column 'ModuleId' cannot be null in ... on line 172
私の質問は、モジュールIDの値を取得してデータベースに挿入できないのはなぜですか？以下はコードです：
session_start();
if (isset($_POST['hiddenmodule'])) {
$_SESSION['hiddenmodule'] = $_POST['hiddenmodule'];
}
if (isset($_POST['id'])) {
$_SESSION['id'] = $_POST['id'];
}
if(isset($_POST['sessionNum'])){
//Declare my counter for the first time
$_SESSION['initial_count'] = $_POST['sessionNum'];
$_SESSION['sessionNum'] = $_POST['sessionNum'];
}
if (!isset($_SESSION['sessionCount'])) {
$_SESSION['sessionCount'] = 1;
}
else if ($_SESSION['sessionCount'] < $_SESSION['sessionNum']) {
++$_SESSION['sessionCount'];
}
$sessionMinus = $_SESSION['sessionCount'];
if (isset($_POST['durationChosen'])) {
$_SESSION['durationChosen'] = $_POST['durationChosen'];
}
if (isset($_POST['dateChosen'])) {
$_SESSION['dateChosen'] = $_POST['dateChosen'];
}
if (isset($_POST['timeChosen'])) {
$_SESSION['timeChosen'] = $_POST['timeChosen'];
}
if (isset($_POST['textQuestion'])) {
$_SESSION['textQuestion'] = $_POST['textQuestion'];
}
if (isset($_POST['textMarks'])) {
$_SESSION['textMarks'] = $_POST['textMarks'];
}
if (isset($_POST['totalWeight'])) {
$_SESSION['totalWeight'] = $_POST['totalWeight'];
}
if (isset($_POST['buildings'])) {
$_SESSION['buildings'] = $_POST['buildings'];
}
if (isset($_POST['rooms'])) {
$_SESSION['rooms'] = $_POST['rooms'];
}
if (isset($_POST['teacherforename'])) {
$_SESSION['teacherforename'] = $_POST['teacherforename'];
}
if (isset($_POST['teachersurname'])) {
$_SESSION['teachersurname'] = $_POST['teachersurname'];
}
if (isset($_POST['teacherusername'])) {
$_SESSION['teacherusername'] = $_POST['teacherusername'];
}
var_dump($_POST);
var_dump($_SESSION);
// connect to the database
include('connect.php');
/* check connection */
if (mysqli_connect_errno()) {
printf("Connect failed: %s\n", mysqli_connect_error());
die();
}
$sql = "
SELECT TeacherId
FROM Teacher
WHERE TeacherUsername = ?
";
if (!$stmt = $mysqli->prepare($sql)) {
// Handle errors with prepare operation here
}
// Bind parameter for statement
$stmt->bind_param("s", $_SESSION['teacherusername']);
// Execute the statement
$stmt->execute();
// This is what matters. With MySQLi you have to bind result fields to
// variables before calling fetch()
$stmt->bind_result($teacherid);
// This populates $teacherid
$stmt->fetch();
// Close the statment
$stmt->close();
if($_SERVER['REQUEST_METHOD'] == 'POST')
{
$time = str_replace(array(' Hrs ', ' Mins ', ' Secs'), array(':', ':', ''), $_SESSION['durationChosen']);
for ($i = 1, $n = $_SESSION['sessionNum']; $i <= $n; $i++) {
$insertsql = "
INSERT INTO Session
(SessionName, SessionTime, SessionDate, SessionWeight, SessionDuration, TotalMarks, ModuleId, TeacherId, Room)
VALUES
(?, ?, ?, ?, ?, ?, ?, ?, ?)
";
if (!$insert = $mysqli->prepare($insertsql)) {
// Handle errors with prepare operation here
}
$sessname = $_SESSION['id'] . ($n == 1 ? '' : $i);
$sessdate = date("Y-m-d", strtotime($_SESSION['dateChosen']));
$insert->bind_param("sssisiiis", $sessname, $_SESSION['timeChosen'], $sessdate,
$_SESSION['totalWeight'], $time, $_SESSION['textMarks'],
$_SESSION['hiddenmodule'], $teacherid, $_SESSION['rooms']);
$insert->execute();
if ($insert->errno) {
// Handle query error here
}
$insert->close();
}
}
以下はvar_dump($_SESSION)出力です。
array(17) {
["teacherid"]=> int(49)
["teacherusername"]=> string(8) "u0867587"
["teacherforename"]=> string(5) "Bruce"
["teachersurname"]=> string(5) "Finch"
["id"]=> string(5) "XNTLR"
["initial_count"]=> string(1) "1"
["sessionNum"]=> string(1) "1"
["sessionCount"]=> int(1)
["durationChosen"]=> string(22) "02 Hrs 00 Mins 00 Secs"
["dateChosen"]=> string(10) "15-12-2012"
["timeChosen"]=> string(5) "10:00"
["textQuestion"]=> string(1) "1"
["textMarks"]=> string(1) "5"
["totalWeight"]=> string(1) "0"
["buildings"]=> string(14) "Canalside East"
["rooms"]=> string(7) "CE01/04"
["hiddenmodule"]=> NULL }