Question

I currently have a form with over 50+ fields, with roughly 20 optional fields.

Is there any easy way to process $_POST data in one hit to remove empty strings and change them to NULL prior to inserting into the database, or do they have to be done one by one in the following method:

if ($_POST['field_x'] == "") {
    $_POST['field_x'] = NULL;
}

Answer 1

You can use array_filter:

$post = array_filter($_POST);

http://php.net/manual/en/function.array-filter.php

If no callback is supplied, all entries of input equal to FALSE (see converting to boolean) will be removed.

To only remove empty strings you can use:

function drop_empty($var)
{
  return ($var === '') ? NULL : $var;
}

$post = array_filter($_POST, 'drop_empty');

If you don’t want to drop values, but only want to set them to NULL: use array_map:

$post = array_map('drop_empty', $_POST);