CREATE TABLE first_notification_of_loss (fnol_id NUMBER, customer_id NUMBER, policy_id NUMBER, service_id NUMBER)
CREATE TABLE claims (claim_id NUMBER, fnol_id NUMBER, effective_date TIME)
CREATE TABLE settlements (settlement_id NUMBER, claim_id NUMBER, effective_date TIME, settlement_amount NUMBER)
CREATE TABLE customers_policies (customer_id NUMBER, policy_id NUMBER, date_opened TIME, date_closed TIME)
CREATE TABLE available_policies (policy_id NUMBER, policy_type_code CLOB, customer_phone CLOB)
CREATE TABLE customers (customer_id NUMBER, customer_name CLOB)
CREATE TABLE services (service_id NUMBER, service_name CLOB)

Find the names of users who do not have a first notification of loss record.
SELECT customer_name FROM customers EXCEPT SELECT t1.customer_name FROM customers AS t1 JOIN first_notification_of_loss AS t2 ON t1.customer_id = t2.customer_id
SELECT "customer_name" FROM "customers" EXCEPT SELECT "t1"."customer_name" FROM "customers" "t1" JOIN "first_notification_of_loss" "t2" ON "t1"."customer_id" = "t2"."customer_id"