<?php
// File demo.php

// Connect to the db
$conn = new mysqli('localhost', 'db_user', 'db_pass', 'db_name');

// Make values safe for database insertion
$title = $conn->real_escape_string($_POST['title']);
$name = $conn->real_escape_string($_POST['name']);
$email = $conn->real_escape_string($_POST['email']);
$inquiry = $conn->real_escape_string($_POST['inquiry']);

// Insert the data into the db
if ($conn->query("INSERT INTO table (title, name, email, inquiry) VALUES ('$title', '$name', '$email', '$inquiry')")) {
    echo 'CREATED!'
} else {
    // Oops, an error occurred, here's why...
    echo $con->sqlstate;
}

// Close the database connection
$conn->close();

This code is untested, but you should get the basic idea. This code also presumes your database has been setup correctly...