I am not sure what the safest way is to get the value of a textarea into a MySQL table, hopefully someone can get me on the right track.

Form:

<form class="form-horizontal" id="form_textarea" action="<?php echo htmlspecialchars($_SERVER["PHP_SELF"]); ?>" method="POST">
  <fieldset>
    <div class="col-12"><label name="textarea" class="control-label ">Textarea</label></div>
    <div class="col-12"><textarea class="form-control" id="textarea" name="textarea" rows="5"></textarea></div>
    <div class="row-12">
      <input type="hidden" id="id" name="id" value="<?php echo $_SESSION["id"]; ?>">
      <input type="submit" name="submit" value="Upload textarea" />
    </div>
    <div id="error" class="error" style="display: none;">Sorry, something went wrong!</div>
  </fieldset>
</form>

jQuery:

<script type="text/javascript">
$(document).ready(function() {
  var v = jQuery("#form_bedrijfsomschrijving").validate({   
    submitHandler: function(form) {
    var formData = new FormData(form);
    // e.preventDefault();
    $.ajax({
      url: "ajax_textarea.php",
      type: "POST",
      data: formData,
      contentType: false,
      cache: false,
      processData:false,
      success: function(data) {
        if(data === 'success') {
          alert('success');
          location.href = 'index.php';
        }
        if(data === 'error') {            
          alert('error');
          $("#error").show();
        }
      },
      error: function(){}           
      });       
    }
  }); 
});      
</script>

ajax_textarea.php:

<?php

$stmt = $link->prepare("UPDATE table SET textarea = ? WHERE id = ?");
$stmt->bind_param("si", $textarea, $id);
$textarea = mysqli_real_escape_string($conn, ucfirst($_POST["textarea"]));
$id       = mysqli_real_escape_string($conn, $_POST["id"]);
$stmt->execute();

if ($stmt->affected_rows == 1) { 
    echo "success";
} else {
    echo "error";
}

$stmt->close(); 
$conn->close();

?>

I am inserting the textarea with this sample text:

This is a test.
Some text on one new line.

And some text after two 2 new lines.

This is what I get in the database:

This is a test.\r\nSome text on one new line.\r\n\r\nAnd some text after two 2 new lines.

First question: Is the \r\n OK in the table?

And the second question: How do I get this field on my screen, viewing exact the same as has been filled in so with the new lines?

I have tried nl2br but when I echo this I see the \r\n in stead of

The textarea field in the database is an text type with utf8_unicode_ci as charset.