CREATE TABLE customers (customer_name VARCHAR(255), customer_phone VARCHAR(255), customer_id VARCHAR(255)); CREATE TABLE mailshot_customers (customer_name VARCHAR(255), customer_phone VARCHAR(255), customer_id VARCHAR(255))
Show the name and phone of the customer without any mailshot.
    
SQL: SELECT customer_name, customer_phone FROM customers WHERE NOT customer_id IN (SELECT customer_id FROM mailshot_customers)