Crud insert method - php

Question

I am creating a database for employees, and I am applying the crud operation to it
The problem with the code is that I cannot insert data into the database from the fields, I also get this error:
do not access superglobal $_post array directly.
<?php
session_start();
include("configa.php");
if ($_SERVER["REQUEST_METHOD"] == "POST") {
$FirstName = filter_input(INPUT_POST, $_POST["FirstName"]);
$LastName = filter_input(INPUT_POST, $_POST["LastName"]);
// attempt insert query execution
$sql = "INSERT INTO employeeinfo (FirstName, LastName) VALUES ('$FirstName', '$LastName')";
if(mysqli_query($mysqli, $sql)){
echo "Records added successfully.";}
else{
echo "ERROR: Could not able to execute $sql. " . mysqli_error($mysqli);
}
// close connection
$sql = 'INSERT INTO `employeeinfo`(`FirstName`, `LastName`) ';
$sql = $sql . "VALUES (\"$FirstName\", \"$LastName\") ";
if ($mysqli->query($sql) === TRUE) {
echo "New record created successfully";
$_SESSION['completed'] = "YES";
} else {
echo "Error: " . $sql . "<br>" . $mysqli->error;
}
header('Location: Employee.php');
}else
{
echo 'BYE BYE !!!';
}
mysqli_close($mysqli);
?>

Answer 1

So the filter_input() method in php accepts a third parameter specifying what it should do as a filtering function. You could go with the filter FILTER_SANITIZE_STRING, judging by your case.
Refer the filter_array method in php manual : http://php.net/manual/en/function.filter-input.php
Refer what filters are available in php : http://php.net/manual/en/filter.filters.php
What Filter am I using for this demo : http://php.net/manual/en/filter.filters.sanitize.php
So your input assignment to variables will look like the following,
$FirstName = filter_input(INPUT_POST, $_POST["FirstName"], FILTER_SANITIZE_STRING);
$LastName = filter_input(INPUT_POST, $_POST["LastName"], FILTER_SANITIZE_STRING);
And i gather you might be using NetBeans for PHP development (https://blogs.oracle.com/netbeansphp/entry/improve_your_code_with_new). This has the same warning as you've mentioned. But I'm not quite sure you will see the warning around other IDE's.