在SQL WHERe中添加PHP变量

您还需要绑定

couponCode

if ($couponCode == $coupons_db3['coupon_pre']){       echo $couponCode;       $stmt = $db->prepare('UPDATE promopre_3 SET used = 1 WHERe coupon_pre =:couponCode');       $stmt->bindValue(':couponCode', $couponCode, PDO::PARAM_STR);       $stmt->execute();       $stmt = $db->prepare('UPDATE usr_customer_profile SET packageid = 3 WHERe usrcustomerid = :usrcustomerid');       $stmt->bindValue(':usrcustomerid', $_SESSION['usrcustomerid'], PDO::PARAM_INT);       $stmt->execute();       break;     }