Parameterised Query For Text Input - php

Question

I have a form with text input fields & select dropdowns which submits information to profile-updated.php. It worked as a simple UPDATE query but I tried to make it into a parameterised query and it does not work. It doesn't give me an error, it just doesn't actually update anything. I did a tutorial for a parameterised SELECT or INSERT query so I probably messed something up when trying to make it suit my UPDATE needs with the "$_POST['age'];" portion. Any help hugely appreciated.
Here is the attempted parameterised query code:
$age = $_POST['age'];
$gender = $_POST['gender'];
$videourl = $_POST['videourl'];
$soundcloud = $_POST['soundcloud'];
$about = $_POST['about'];
$facebook = $_POST['facebook'];
$twitter = $_POST['twitter'];
$stmt = $con->stmt_init();
if ($stmt->prepare("UPDATE Users1 (age, gender, videourl, soundcloud,
about, facebook, twitter) VALUES (?, ?, ?, ?, ?, ?, ?) WHERE email = '" . $_POST['email'] . "' ")) {
$stmt->bind_param("sssssss", $age, $gender, $videourl, $soundcloud, $about, $facebook, $twitter);
$stmt->execute();
$stmt->close();
}
$con->close();
Here is my old update code that worked fine:
$sql = mysqli_query($con, "UPDATE Users1
SET age = '" . $_POST['age'] . "',
gender = '" . $_POST['gender'] . "',
videourl = '" . $_POST['videourl'] . "',
soundcloud = '" . $_POST['soundcloud'] . "',
about = '" . $_POST['about'] . "',
facebook = '" . $_POST['facebook'] . "',
twitter = '" . $_POST['twitter'] . "',
WHERE email = '" . $_POST['email'] . "'
");

Answer 1

I think the syntax of your update statement is incorrect. Your 'old update code' uses the correct one.
That syntax is more appropriate to the 'insert' statement.
Try:
$stmt->prepare( "update users1 set age = ?, gender = ?, ... where email = ?" );
$stmt->bind_param( ... , $_POST[ 'age' ] );
and so on.