Database: museum_visit
Question: What are the id, name and membership level of visitors who have bought the largest num of ticket 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.num_of_ticket) desc limit 1