What is the name of the customer who has been involved in most policies?
select t2.customer_details from policies as t1 join customers as t2 on t1.customer_id = t2.customer_id group by t2.customer_details order by count ( * ) desc limit 1
What is her ID?
select t2.customer_id from policies as t1 join customers as t2 on t1.customer_id = t2.customer_id group by t2.customer_details order by count ( * ) desc limit 1
How many policies has she been involved in ?
select count ( * ) from policies as t1 join customers as t2 on t1.customer_id = t2.customer_id group by t2.customer_details order by count ( * ) desc limit 1