Question: What are the id, name and membership level of visitors who have spent the largest amount of money in total in all museum tickets?
SQL: SELECT t2.visitor_id ,  t1.name ,  t1.Level_of_membership FROM visitor AS t1 JOIN visit AS t2 ON t1.id  =  t2.visitor_id GROUP BY t2.visitor_id ORDER BY sum(t2.Total_spent) DESC LIMIT 1