//insert this php code, at the end after your closing html tag.
<?php
//setting connection to database
$con = mysqli_connect("localhost","your-username","your-
passowrd","your-dbname");
if(isset($_POST['submit_button'])){
$txt_area = $_POST['update'];
$Our_query= "INSERT INTO your-table-name (field1name, field2name)
VALUES ('abc','def')"; // values should match data
// type to field names
$insert_query = mysqli_query($con, $Our_query);
if($insert_query){
echo "<script>window.open('form.php','_self') </script>";
// supposing form.php is where you have created this form
}
} //if statement close
?>
Hope this helps.