نحوه ارسال کاراکتر UTF-8 از PHP به دیتابیس

$comment_ID = "";
$comment_post_ID = 2289;
$comment_author = "محمد";
$comment_author_email = "[email protected]";
$comment_author_url = "";
$comment_author_IP = 0;
$comment_date = "2016-09-28 20:41:35";
$comment_date_gmt = "2016-09-28 20:41:35";
$comment_content = "تست پيام از سمت برنامه نويسي";
$comment_karma = 0;
$comment_approved = 0;
$comment_agent = "";
$comment_type = "";
$comment_parent = 0;
$user_id = 0;

$sql_query = "INSERT INTO qpHskU_Idea VALUES ('$comment_ID', '$comment_post_ID', '$comment_author', '$comment_author_email',
'$comment_author_url', '$comment_author_IP', '$comment_date', '$comment_date_gmt', '$comment_content',
'$comment_karma', '$comment_approved', '$comment_agent', '$comment_type', '$comment_parent', '$user_id');";

if(mysqli_query($con,$sql_query)){
echo "Record added successfully.";
} else {
echo "Record not added..." . mysqli_error($con);
}

?>