/**
* DEPRECATED- this seemed like a good idea at the time, but we're now doing it using CSV lists
* Associates students with an exam instance ID by cohort
* @global type $CFG
* @param type $id
* @param type $studentID The ID of the student to associate
* @return XML-formatted string containing details of the student, or an error if the insert query fails
*/
public function associateStudentsWithInstanceByCohort($id, $cohortID)
{
global $CFG;
$conn = mysqli_connect($CFG->db, $CFG->dbuser, $CFG->dbuserpass, $CFG->schema) or die('<data><error>failed connecting to database</error><detail>' . mysqli_error($conn) . '</detail></data>');
// get all students belonging to a cohort
$query = "SELECT ID FROM students WHERE cohort = {$cohortID};";
$result = mysqli_query($conn, $query) or die('<data><error>lookup query failed</error><detail>' . mysqli_error($conn) . $query . '</detail></data>');
while ($row = mysqli_fetch_array($result)) {
// check to see we're not doubling up
$checkQuery = "SELECT * FROM student_exam_instance_link WHERE students_ID = {$row['ID']} AND exam_instances_ID = {$id}";
$checkresult = mysqli_query($conn, $checkQuery) or die('<data><error>check query failed</error><detail>' . mysqli_error($conn) . $checkQuery . '</detail></data>');
// print("result count:".mysqli_num_rows($checkresult));
if (mysqli_num_rows($checkresult) == 0) {
// print('inserting...');
$query = "INSERT INTO {$CFG->schema}.student_exam_instance_link (exam_instances_ID, students_ID) \n VALUES({$id}, {$row['ID']});";
$result2 = mysqli_query($conn, $query) or die('<data><error>insert query failed</error><detail>' . mysqli_error($conn) . $query . '</detail></data>');
}
}
if (mysqli_insert_id($conn) > 0) {
// return all just added
$enumlib = new EnumLib();
return $enumlib->getStudentsByCohortIDAssociatedWithInstance($id, $cohortID);
} else {
return '<data><error>associateStudentsWithInstanceByCohort operation failed</error><detail>' . mysqli_error($conn) . '</detail></data>';
}
// return "<data><id>$returnStr</id></data>";
}
