SQL Syntax Error after updating to WordPress 4.8.2 - mysql

Question

I have been using a hook in the Advanced Custom Fields plugin (load_field) which loads objects from a table in my database to an ACF select field. The table ('wp_new_royalsliders') is created by the RoyalSlider image slider plugin so i use the hook to populate a select field with the slider names.
This function has worked fine for a long time but recently stopped working - I think after updating core to 4.8.2:
add_filter('acf/load_field/name=media_gallery_slider', 'my_acf_royalslider_choices');
function my_acf_royalslider_choices($field){
$field['choices'] = array();
global $wpdb;
$query = $wpdb->prepare('SELECT * FROM %1$s ORDER BY ID ASC', 'wp_new_royalsliders');
$results = $wpdb->get_results($query);
if(!empty($results)) :
foreach($results as $result) :
$value = $result->id;
$label = $result->name;
$field['choices'][ $value ] = $label;
endforeach;
endif;
return $field;
}
When I turn debugging on I get an error:
WordPress database error: [You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '%1$s ORDER BY ID ASC' at line 1]
SELECT * FROM %1$s ORDER BY ID ASC

Answer 1

When you pass in a hardcoded string value, you don't need placeholders, you can just use
$query = $wpdb->prepare('SELECT * FROM wp_new_royalsliders ORDER BY ID ASC');
If you want to get fancy and portable, you might opt for
$query = $wpdb->prepare('SELECT * FROM ' . $wpdb->prefix . 'new_royalsliders ORDER BY ID ASC');
So it would work on other prefixes, too, but that might not be necessary if this is a very custom thing that's not going to make it into any other site.
It appears that others have noted the removal of that possibility too, see this request.
Update: as $wpdb->prepare() expects a second parameter (since its job is to escape variable inputs for use in SQL), it might complain. Solution: get rid of it and give your SQL directly to get_results:
$results = $wpdb->get_results('SELECT * FROM ' . $wpdb->prefix . 'new_royalsliders ORDER BY ID ASC');