1581. Customer Who Visited but Did Not Make Any Transactions : Leetcode

1581. Customer Who Visited but Did Not Make Any Transactions

# 01. count customer's visit from Visits table
select customer_id, count(customer_id)
from Visits 
group by customer_id;


# 02. count visit_id from transaction
select visit_id, count(transaction_id) 
from Transactions
group by visit_id;


select customer_id, count(visit_id) as count_no_trans
from Visits
where visit_id not in (select distinct visit_id from Transactions)
group by customer_id;