set input max length with php - php

Question

I'm trying to set a max value to my inputs. I can do it with html but anyone can easily overwrite that in any browser's inspect menu. So I want to use php to set it. I don't really know where I should put it and if this is the right way or not.
<?php
$link = mysqli_connect("localhost", "root", "", "reg");
mysqli_set_charset($link, "utf8");
// Check connection
if($link === false){
die("ERROR: Could not connect. " . mysqli_connect_error());
}
// Escape user inputs for security
$name = mysqli_real_escape_string($link, $_REQUEST['name']);
$job = mysqli_real_escape_string($link, $_REQUEST['job']);
$email = mysqli_real_escape_string($link, $_REQUEST['email']);
$phone = mysqli_real_escape_string($link, $_REQUEST['phone']);
$phone2 = mysqli_real_escape_string($link, $_REQUEST['phone2']);
$address = mysqli_real_escape_string($link, $_REQUEST['address']);
$description = mysqli_real_escape_string($link, $_REQUEST['description']);
$visibility = mysqli_real_escape_string($link, $_REQUEST['visibility']);
// attempt insert query execution
$sql = "INSERT INTO cards (name, job, email, phone, phone2, address, description, visibility) VALUES ('$name', '$job', '$email', '$phone', '$phone2', '$address', '$description', '$visibility')";
if(mysqli_query($link, $sql)){
header("Location: addbusiness.php?message=1");
} else{
echo "ERROR: Could not able to execute $sql. " . mysqli_error($link);
}
if(strlen($name) > 10)
{
echo "Max value is 10";
}
// close connection
mysqli_close($link);
?>
<label>Name</label>
<input class="form-control" id="name" name="name" type="text" required="required">

Answer 1

You need to do the strlen() check before you perform the insert, and not insert anything if the check fails.
if(strlen($name) > 10)
{
echo "Max value is 10";
exit();
}
// attempt insert query execution
$sql = "INSERT INTO cards (name, job, email, phone, phone2, address, description, visibility) VALUES ('$name', '$job', '$email', '$phone', '$phone2', '$address', '$description', '$visibility')";
if(mysqli_query($link, $sql)){
header("Location: addbusiness.php?message=1");
} else{
echo "ERROR: Could not able to execute $sql. " . mysqli_error($link);
}