Context: CREATE TABLE first_notification_of_loss (customer_id VARCHAR, service_id VARCHAR); CREATE TABLE customers (customer_name VARCHAR, customer_id VARCHAR); CREATE TABLE services (service_id VARCHAR, service_name VARCHAR)
Question: Find the names of customers who have used both the service "Close a policy" and the service "New policy application".
Answer: SELECT t1.customer_name FROM customers AS t1 JOIN first_notification_of_loss AS t2 ON t1.customer_id = t2.customer_id JOIN services AS t3 ON t2.service_id = t3.service_id WHERE t3.service_name = "Close a policy" INTERSECT SELECT t1.customer_name FROM customers AS t1 JOIN first_notification_of_loss AS t2 ON t1.customer_id = t2.customer_id JOIN services AS t3 ON t2.service_id = t3.service_id WHERE t3.service_name = "New policy application"