我的函数需要什么参数来回显get_results（）查询结果

This is my WordPress database query:

global $wpdb;

$table_name = $wpdb->prefix . 'qs_css';
$db_css = $wpdb->get_results( 
    "
    SELECT qs_the_css 
    FROM $table_name
    WHERE qs_css_id = 1 
    "
);

echo $db_css[0]->qs_the_css;  // WORKS JUST FINE

However, I need the query results inside my function:

add_action( 'wp_head', 'quick_qs_db_css', 100 );
function quick_qs_db_css(  ) { ?>

<style type="text/css" id="db-css">
<?php echo $db_css[0]->qs_the_css; // OUTPUTS NILL ! ?>
</style>

<?php }

What arguments does the quick_qs_db_css() function need ? Is it possible to pass query results to a function?

I would prefer not to include the query inside the quick_qs_db_css() function.

Update:

add_action( 'wp_head', 'quick_qs_db_css', 100 );
function quick_qs_db_css( $db_css ) { ?>


<?php var_dump( $db_css[0]->qs_the_css); // ALSO RETURNS NULL ?>  


<?php }

Any input would be very much appreciated ! Thanking in advance :)

Firstly, inside function the $db_css have a local visibility and the variable isn't visible inside the function. So, you should pass the $db_css variable as argument.