How can using variables like $_POST['XXX'] instead of direct variables improve data insertion in PHP?

Using variables like $_POST['XXX'] instead of direct variables can improve data insertion in PHP by providing an added layer of security against SQL injection attacks. By sanitizing and validating user input through $_POST variables, we can ensure that only expected and safe data is being inserted into our database, reducing the risk of malicious code being executed.

// Example of using $_POST variables for data insertion
$name = $_POST['name'];
$email = $_POST['email'];

// Sanitize and validate input before inserting into database
$name = filter_var($name, FILTER_SANITIZE_STRING);
$email = filter_var($email, FILTER_VALIDATE_EMAIL);

// Perform database insertion using sanitized data
// $sql = "INSERT INTO users (name, email) VALUES ('$name', '$email')";
// mysqli_query($connection, $sql);