Inserting Form Data into SQL table

Question

I've been trying to figure this out for hours and it seems like there are multiple ways of doing it but for some reason I can't seem to get it to work correctly. For some reason my table is being updated and I am only seeing new rows with a new auto increment integer but the remaining columns are left blank. There is a bit more to that form but I left it off to keep this as short as possible. Thanks for the help!

File: dbh.inc.php

$dbServername = "localhost";
$dbUsername = "username";
$dbPassword = "password";
$dnName = "database_name";


$conn = mysqli_connect($dbServername, $dbUsername, 
$dbPassword, $dnName);
if(!$conn)
// creation of the connection object failed
die("connection object not created: ".mysqli_error($conn));
// Check connection
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
}
echo "Connected successfully";

File with form:

$name7 = $_POST['name7'];
$email7 = $_POST['email7'];
$phone7 = $_POST['phone7'];
$message7 = $_POST['message7'];


$sql = "INSERT INTO user_contacts (name7, email7, phone7, message7) VALUES ('".$_POST["name7"]."','".$_POST["email7"]."','".$_POST["phone7"]."','".$_POST["message7"]."')"; 
mysqli_query($conn, $sql);
 ?>
            <div class="form-group">
                <form action="dbh.inc.php" method="POST">
                <input type="text" class="form-control" name="name7" id="name7" placeholder="<?php esc_html_e('Name:','listingpro'); ?>">
                <span id="name7"></span>
            </div>

            <div class="form-group form-group-icon">
                <i class="fa fa-envelope" aria-hidden="true"></i>
                <input type="email" class="form-control" name="email7" id="email7" placeholder="<?php esc_html_e('Email:','listingpro'); ?>">

            </div>

            <div class="form-group">
                <input type="text" class="form-control" name="phone7" id="phone7" placeholder="<?php esc_html_e('Phone','listingpro'); ?>">
                <span id="phone7"></span>
            </div>

            <div class="form-group">
                <textarea class="form-control" rows="5" name="message7" id="message7" placeholder="<?php esc_html_e('Message:','listingpro'); ?>"></textarea>
            </div>

Answer 1

I have Just Edited your sql a little bit. Try It

      $sql = "INSERT INTO user_contacts (name7, email7, phone7, message7) VALUES ('". 
      $name7. "','" . $email7 .  "','". $phone7 ."','". $message ."')";