Get the SKU in a Product list sales report

— Light Update —

You can add the sku changing a little bit your code this way:

$args = array(    'post_type' => 'product',    'posts_per_page' => -1,    'meta_key' => 'total_sales',    'orderby' => 'meta_value_num',    'order' => 'DESC',    'meta_query' => array(        array(            'key' => 'total_sales',            'value' => 0,            'compare' => '>'        )    ));$output = array_reduce( get_posts( $args ), function( $result, $post ) {    return $result .= '    <tbody>        <tr>            <td>' . $post->post_title . '</td>            <td>' . get_post_meta( $post->ID, "total_sales", true ) .'</td>            <td>' . get_post_meta( $post->ID, "_sku", true ) .'</td>         </tr>    </tbody>';} );echo '<table>    <thead>        <tr>            <th>' . __( "Product", "woocommerce" ) . '</th>            <th>' . __( "Units Sold", "woocommerce" ) . '</th>            <th>' . __( "Sku", "woocommerce" ) . '</th>        </tr>    </thead>' . $output . '</table>';

I am using here get_post_meta( $post->ID, "_sku", true ) to get the SKU value from wp_postmeta database table…

Or alternatively you can use with a product object the method get_sku()…