query: SELECT customer_details FROM customers EXCEPT SELECT t2.customer_details FROM policies AS t1 JOIN customers AS t2 ON t1.customer_id  =  t2.customer_id
question: Find the names of customers which have no policies associated.
query_toks: SELECT customer_details FROM customers EXCEPT SELECT t2.customer_details FROM policies AS t1 JOIN customers AS t2 ON t1.customer_id = t2.customer_id
query_toks_no_value: select customer_details from customers except select t2 . customer_details from policies as t1 join customers as t2 on t1 . customer_id = t2 . customer_id
question_toks: Find the names of customers which have no policies associated.