What potential pitfalls should be avoided when using PHP to handle form submissions?

One potential pitfall to avoid when using PHP to handle form submissions is not properly sanitizing user input, which can leave your application vulnerable to security threats such as SQL injection attacks. To prevent this, always use functions like mysqli_real_escape_string() or prepared statements to sanitize user input before using it in database queries. 

// Example of using mysqli_real_escape_string() to sanitize user input before using it in a database query
$conn = new mysqli($servername, $username, $password, $dbname);

// Check connection
if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error);
}

// Sanitize user input
$name = mysqli_real_escape_string($conn, $_POST['name']);
$email = mysqli_real_escape_string($conn, $_POST['email']);

// Insert sanitized data into database
$sql = "INSERT INTO users (name, email) VALUES ('$name', '$email')";
if ($conn->query($sql) === TRUE) {
    echo "New record created successfully";
} else {
    echo "Error: " . $sql . "<br>" . $conn->error;
}

$conn->close();

Keywords

SQL injection cross-site scripting form validation CSRF attacks error handling

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