Erreur !: SQLSTATE[23000]: Integrity constraint violation: 1048 Column 'id_type_

<form method="post" id="saisie" action="./?action=couter" onsubmit="return valider()">
        <br/>
        <div class="form-group">
            <label for="quotient"class="label">Cout</label>
            <input type="text" class="form-control" name="montant" id="montant" placeholder="0">
            </br>
            <label for="">Tranches: </label>
            <select name="tranchesC" id="tranchesC">
            <option value="">..Tranche..</option>
                <?php for ($i = 0; $i < count($getTranche); $i++) {?>
                    <option value="<?= $i; ?>">
                        <?= $getTranche[$i]["id"];?>
                    </option>
                <?php } ?>
            </select>
            <label for="">Type de Cours: </label>
            <select name="typeCour" id="typeCour">
            <option value="">..Type de cour..</option>
                <?php for ($i = 0; $i < count($getTypeCour); $i++) {?>
                    <option value="<?= $i; ?>">
                        <?=$getTypeCour[$i]["libelle"];?>
                    </option>
                <?php } ?>
            </select>
        </div>
        <button name="bouton" id="bouton" type="submit" class="btn btn-primary">Envoyer</button>
</form>

$couter = $_POST['montant'];
$tranche=$_POST['tranchesC'];
$typeCour=$_POST['typeCour'];

function InsertCouter($couter,$tranche,$typeCour){
    try {
        $cnx = connexionPDO();
        $req = $cnx->prepare("Insert into couter(montant,id_tranches,id_type_cour) Value(:montant,(Select id from tranches where id=:tranche),(Select id from type_cour where id=:typeCour))");
        $req->bindValue(':montant', $couter, PDO::PARAM_INT);
        $req->bindValue(':tranche', $tranche, PDO::PARAM_INT);
        $req->bindValue(':typeCour', $typeCour, PDO::PARAM_INT);

        $resultat = $req->execute();
    } catch (PDOException $e) {
        print "Erreur !: " . $e->getMessage();
        die();
    }

$req = $cnx->prepare("Insert into couter(montant,id_tranches,id_type_cour) Value(:montant,(Select id from tranches where id=:tranche),(Select id from type_cour where id=:typeCour))");

Select id from type_cour where id=:typeCour

$sql = "Insert into couter(montant,id_tranches,id_type_cour)
             Value(:montant, :tranche, :typeCour )";
$req = $cnx->prepare($sql);