PHP - Insert into database issue - php

Question

I am trying to input data into a database.
i have used echo to see if the database is being read, it is and the database echo's as entered, it just does not insert into the database. This is the same code i used for the registration page, apart from a new amendments, and my reg page works perfectly so i am a little confused to why it is not working.
HTML
<!-- <div id="first">-->
<input type="text" id="fname" name="fname" value="" required>
<input type="text" id="lname" name="lname" value="" required>
<input type="text" id="email" name="email" value="" required>
<input type="number" id="phone" name="phone" value="" required>
<input type="submit" name="Update" value="Update">
<br>
PHP
<?php
session_start();
require('../mysql.inc.php');
?>
<?php
if (isset($_POST['Update'])) {
echo $c_fname = $_POST['fname'];
echo $c_lname = $_POST['lname'];
echo $c_email = $_POST['email'];
echo $c_phone = $_POST['phone'];
$insert_det = "INSERT INTO Cus_acc_details(CUS_Fname,CUS_Lname,CUS_Phone,Cus_Email) VALUES (?,?,?,?)";
$stmt = mysqli_prepare($dbc, $insert_det);
mysqli_stmt_bind_param($stmt, 'sssi', $c_fname, $c_lname, $c_email, $c_phone);
if ($insert_det) {
echo " Saved";
}
} else {
echo "<b> Error </b>";
}
?>
Any suggestions

Answer 1

The call to mysqli_stmt_execute() is missing, thus your statement will never be executed.

Answer 2

Try changing your insert query to
$insert_det = "INSERT INTO Cus_acc_details(CUS_Fname,CUS_Lname,Cus_Email,CUS_Phone) VALUES (?,?,?,?)";
$stmt = mysqli_prepare($dbc, $insert_det);
As you are mixing them up when declaring them on the placeholders and are casting email as a integer but trying to insert the phone number as the email and vice versa