julianjupiter/student_course.php

## student_course.php
<?php
try {
    $connection = new PDO('mysql:host=localhost;dbname=jtest2', 'root', 'admin123');
} catch (PDOException $e) {
    echo $e->getMessage();
}
try {
    $querySelect = 'SELECT id, course_type FROM course_type';
    $statementSelect = $connection->prepare($querySelect);
    $statementSelect->execute();
    $data = $statementSelect->fetchAll();
} catch (PDOException $e) {
    echo $e->getMessage();
}
$message = '';
if (isset($_POST['btnSave'])) {
     if (!empty($_POST['subjectInserting'])) {
         $counter = 0;
         foreach ($_POST['subjectInserting'] as $subject) {
            try {
                $queryInsert = 'INSERT INTO student_info(subject_name) VALUES(:subject_name)';
                $statementInsert = $connection->prepare($queryInsert);
                $result = $statementInsert->execute([':subject_name' => $subject]);
                if ($result) {
                    $counter += 1;
                }
            } catch (PDOException $e) {
                echo $e->getMessage();
            }
         }

         $message = $counter . ' subject(s) saved!';
    }
}
?>
<!doctype html>
<html>
    <head>
    </head>
    <body>
        <form method="post">
            <table>
                <tr>
                    <td>
                        <select name="subjectNames[]" multiple>
                        <?php
                        foreach ($data as $d) {
                        ?>
                            <option value="<?php echo $d['id'];?>"><?php echo $d['course_type'];?></option>
                        <?php
                        }
                        ?>
                        </select>

                    </td>
                    <td>
                        <button type="submit" name="btnTransfer">&gt;</button>
                    </td>
                    <td>
                        <select name="subjectInserting[]" multiple>
                        <?php
                        if (isset($_POST['btnTransfer'])) {
                            foreach ($_POST['subjectNames'] as $selectedSubject) {
                        ?>
                                <option value="<?php echo $selectedSubject;?>"><?php echo $selectedSubject;?></option>
                        <?php
                            }
                        }
                        ?>
                        </select>
                    </td>
                    <td>
                        <button type="submit" name="btnSave">Save</button>
                    </td>
                    <?php
                    if ($message != '') {
                    ?>
                    <td>
                        <p><?php echo $message;?></p>
                    </td>
                    <?php } ?>
                </tr>
            </table>
        </form>
    </body>
</html>
	<?php
	try {
	$connection = new PDO('mysql:host=localhost;dbname=jtest2', 'root', 'admin123');
	} catch (PDOException $e) {
	echo $e->getMessage();
	}
	try {
	$querySelect = 'SELECT id, course_type FROM course_type';
	$statementSelect = $connection->prepare($querySelect);
	$statementSelect->execute();
	$data = $statementSelect->fetchAll();
	} catch (PDOException $e) {
	echo $e->getMessage();
	}
	$message = '';
	if (isset($_POST['btnSave'])) {
	if (!empty($_POST['subjectInserting'])) {
	$counter = 0;
	foreach ($_POST['subjectInserting'] as $subject) {
	try {
	$queryInsert = 'INSERT INTO student_info(subject_name) VALUES(:subject_name)';
	$statementInsert = $connection->prepare($queryInsert);
	$result = $statementInsert->execute([':subject_name' => $subject]);
	if ($result) {
	$counter += 1;
	}
	} catch (PDOException $e) {
	echo $e->getMessage();
	}
	}

	$message = $counter . ' subject(s) saved!';
	}
	}
	?>
	<!doctype html>
	<html>
	<head>
	</head>
	<body>
	<form method="post">
	<table>
	<tr>
	<td>
	<select name="subjectNames[]" multiple>
	<?php
	foreach ($data as $d) {
	?>
	<option value="<?php echo $d['id'];?>"><?php echo $d['course_type'];?></option>
	<?php
	}
	?>
	</select>

	</td>
	<td>
	<button type="submit" name="btnTransfer">></button>
	</td>
	<td>
	<select name="subjectInserting[]" multiple>
	<?php
	if (isset($_POST['btnTransfer'])) {
	foreach ($_POST['subjectNames'] as $selectedSubject) {
	?>
	<option value="<?php echo $selectedSubject;?>"><?php echo $selectedSubject;?></option>
	<?php
	}
	}
	?>
	</select>
	</td>
	<td>
	<button type="submit" name="btnSave">Save</button>
	</td>
	<?php
	if ($message != '') {
	?>
	<td>
	<p><?php echo $message;?></p>
	</td>
	<?php } ?>
	</tr>
	</table>
	</form>
	</body>
	</html>