Paid Memberships Pro - Add discount codes to Member list

gistfile1.txt

/**
 * Hook into Members List header
 */
add_action( 'pmpro_memberslist_extra_cols_header', 'my_pmpro_memberslist_extra_cols_header' );
function my_pmpro_memberslist_extra_cols_header() {
	echo '<th>Discount Code</th>';
}

/**
 * Hook into Members List body to show discount code
 */
add_action( 'pmpro_memberslist_extra_cols_body', 'my_pmpro_memberslist_extra_cols_body' );
function my_pmpro_memberslist_extra_cols_body( $theuser ) {
	global $wpdb;

	// Fetch discount code information
	$sqlQuery = "SELECT c.id, c.code FROM $wpdb->pmpro_discount_codes_uses cu LEFT JOIN $wpdb->pmpro_discount_codes c ON cu.code_id = c.id WHERE cu.user_id = '" . $theuser->ID . "' ORDER BY c.id DESC LIMIT 1";                        
	$discount_code = $wpdb->get_row( $sqlQuery );

	if ( ! empty( $discount_code ) )
		echo '<td class="discount-code discount-code-' . $discount_code->id .'">' . $discount_code->code . '</td>';
	else
		echo '<td class="discount-code"></td>';
}