There are 3 types of adventures for which I used distinct function in query. There is only one 1 customer who have booked all types of adventures. The query i used to fetch the data is:
select c.customerid,c.name
from customer c
inner join booking b
on c.customerid = b.customerid
inner join destination d
on b.destinationid=d.destinationid
inner join adventure a
on d.adventureid=a.adventureid
group by c.customerid
having count(distinct b.bid)=(select count(*) from bid)
or count(distinct a.adventuretype)=(
select count(distinct a.adventuretype)
from adventure
)
You can get the customer ids using aggregation and having:
select b.customerid
from booking b join
destination d
on b.destinationid = d.destinationid join
adventure a
on d.adventureid = a.adventureid
group by b.customerid
having count(distinct a.advtype) = 3;
Or, if you don't want to hardcode the "3", you can use:
having count(distinct a.advtype) = (select count(distinct advtype from adventure)
I'll leave it up to you to add in the customer name (using join, exists, or in).