Requete

$datedebut = !empty($_POST['datedebut'])?$_POST['datedebut']:NULL;
$datefin       = !empty($_POST['datefin'])?$_POST['datefin']:NULL;

$sql = "SELECT *
FROM matable
WHERE monchampdate BETWEEN '$datedebut' AND '$datefin' ";

SELECT *
FROM ma_table
WHERE (ton_champ_date BETWEEN '2015-10-10' AND '2016-10-10');

$sql = "SELECT *
        FROM ma_table
        WHERE (ton_champ_date BETWEEN :datedebut AND :datefin) ;";
$stmt = $instancePDO->prepare($sql);
$stmt->execute(array( ':datedebut'  => $datedebut,
                      ':datefin'    => $datefin ));

$result = $stmt->fetch(PDO::FETCH_OBJ);

$instancePDO= new PDO('mysql:host=localhost;dbname=test', $user, $pass);

$sql = "SELECT *
        FROM ma_table
        WHERE (ton_champ_date BETWEEN :datedebut AND :datefin) ;";
$stmt = $instanceMysqli->prepare($sql);

// On met ss car c'est deux string (i=string, d=double, s=string)
$stmt->bind_param('ss', $datedebut, $datefin);

$stmt->execute();
$result = $stmt->get_result();

$instanceMysqli= new mysqli('localhost', 'my_user', 'my_password', 'my_db');