How to explode data using MYSQL and using NOT IN?

I have a programming code problem, I need help to solve the problem.

How to explode data array using MYSQL and using NOT IN.

The program code is below

<form style="overflow: hidden;" method="post">
    <div class="table-responsive">

    <?php
        $sql = "SELECT * FROM kursus WHERE KodKursus NOT IN 
        (SELECT kursusList FROM pensyarahkursus WHERE IDUser= '$value');";
        $stmt = $db->query($sql);

        $i = 1;
        if ($stmt->rowCount() > 0) { ?>

        <table class="table table-hover table-bordered table-striped" id="dataTable" width="100%" cellspacing="0">
            <thead>
                <tr>
                    <td style="width: 10px;"></td>
                    <th style="width: 20px;">#</th>
                    <td>Semester</td>
                    <td>Kod Kursus</td>
                    <td>Nama Kursus</td>
                </tr>
            </thead>
            <tbody>
            <?php
                while ($row = $stmt->fetch()) {
                    echo "<tr>"; ?>
                <td>
                    <input type="checkbox" aria-label="Checkbox for following text input" name="kursus[]" value="<?php echo $row['IDKursus']; ?>">
                    </td>
                        <th><?php echo $i ?></th>
                        <td><?php echo $row['Semester']; ?></td>
                        <td><?php echo $row['KodKursus']; ?></td>
                        <td><?php echo $row['NamaKursus']; ?></td>
                    <?php 
                        echo "</tr>";
                        $i++; } ?>

                </tbody>
            </table>
            <?php
                } else {
                    echo "<br>";
                    echo "<center><h4> Tiada Rekod</h4></center>";
                } ?>
        </div>
        <div class="d-flex justify-content-between mt-3">
            <button type="submit" class="btn btn-success" name="daftar_kursus">Daftar Kursus</button>
            <button type="reset" class="btn btn-primary">Reset</button>
        </div>
    </div>
</form>

Picture below sample data pensyarahKursus

Picture bewlow sample data from kursus