Database: government_shift
Question: Find the details of the customers who have used the least-used service .
SQL:
select distinct t1.customer_details from customers as t1 join customers_and_services as t2 on t1.customer_id  =  t2.customer_id where t2.service_id  =  (select service_id from services group by service_id order by count(*) asc limit 1)