I am trying to retrieve exams(sessions) depending on the module the teacher has chosen from the previous drop down menu.
For Example:
Module selected from drop down: CHI2332 (ModuleId) Advanced Database Systems (ModuleName)
Exam(Session) shown in drop down:
AAA (SessionId) 24-04-2012 (SessionDate) 11:00:00 (Session Time)
ARF (SessionId) 13-06-2012 (SessionDate) 14:00:00 (Session Time)
EFT (SessionId) 10-09-2012 (SessionDate) 09:00:00 (Session Time)
It should display the exams above in the drop down menu as these exams match the moduleId chosen from the module dropdown menu and the TeacherId for these exams belong to the Teacher Username logged into to this page.
The problem is that in the Exam drop down menu, it cannot seem to find any exams even though the modules are legitimate for those exams and hence it should display those exams in the drop down menu.
It just outputs this error below in its place:
Sessions: Notice: Undefined variable: sessionHTML in /.../ on line 178
How can I get the exams to appear in the drop down menu when it should do?
Below are the database tables:
Session Table:
SessionId SessionDate SessionTime ModuleId
AAA 24-04-2012 11:00:00 CHI2332
ARF 13-06-2012 14:00:00 CHI2332
EFT 10-09-2012 09:00:00 CHI2332
Module Table:
ModuleId ModuleName
CHI2332 Advanced Database Systems
Below is the php/mysqli code:
<?php
// connect to the database
include('connect.php');
/* check connection */
if (mysqli_connect_errno()) {
printf("Connect failed: %s\n", mysqli_connect_error());
die();
}
$courseid = (isset($_POST['courseid'])) ? $_POST['courseid'] : '';
?>
<h1>DELETING AN ASSESSMENT</h1>
<form action="<?php echo htmlentities($_SERVER['PHP_SELF']); ?>" method="post">
<p>Course ID: <input type="text" name="courseid" /><input id="courseSubmit" type="submit" value="Submit" name="submit" /></p>
</form>
<?php
if (isset($_POST['submit'])) {
$query = "
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
";
$qrystmt=$mysqli->prepare($query);
// You only need to call bind_param once
$qrystmt->bind_param("s",$courseid);
// get result and assign variables (prefix with db)
$qrystmt->execute();
$qrystmt->bind_result($dbCourseId,$dbModuleId,$dbCourseName,$dbModuleName);
$qrystmt->store_result();
$num = $qrystmt->num_rows();
if($num ==0){
echo "<p>Sorry, No Course was found with this Course ID '$courseid'</p>";
} else {
$dataArray = array();
while ( $qrystmt->fetch() ) {
// data array
$dataArray[$dbCourseId]['CourseName'] = $dbCourseName;
$dataArray[$dbCourseId]['Modules'][$dbModuleId]['ModuleName'] = $dbModuleName;
// session data
$_SESSION['idcourse'] = $dbCourseId;
$_SESSION['namecourse'] = $dbCourseName;
}
foreach ($dataArray as $courseId => $courseData) {
$output = "";
$output .= "<p><strong>Course:</strong> " . $courseId . " - " . $courseData['CourseName'] . "</p>";
$moduleHTML = "";
$moduleHTML .= '<select name="module" id="modulesDrop">'.PHP_EOL;
$moduleHTML .= '<option value="">Please Select</option>'.PHP_EOL;
foreach ($courseData['Modules'] as $moduleId => $moduleData) {
$moduleHTML .= "<option value='$moduleId'>" . $moduleId . " - " . $moduleData['ModuleName'] ."</option>".PHP_EOL;
}
}
$moduleHTML .= '</select>';
echo $output;
}
?>
<form action="<?php echo htmlentities($_SERVER['PHP_SELF']); ?>" method="post">
<p>Module: <?php echo $moduleHTML; ?><input id="moduleSubmit" type="submit" value="Submit" name="modulesubmit" /></p>
</form>
<?php
}
if (isset($_POST['modulesubmit'])) {
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() ) {
$dataArraySession[$dbModuleId]['Sessions'][$dbSessionId]['SessionDate'] = $dbSesisonDate['SessionTime'] = $dbSessionTime;
}
foreach ($dataArraySession as $sessionId => $sessionData) {
$sessionHTML = "";
$sessionHTML .= '<select name="session" id="sessionsDrop">'.PHP_EOL;
$sessionHTML .= '<option value="">Please Select</option>'.PHP_EOL;
$sessionHTML .= "<option value='$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="Submit" name="sesionsubmit" /></p>
</form>
<?php
}
else {
echo "<p>Sorry, You have No Sessions under this Module</p>";
}
}
?>
Link to application is here: Application