Schema: CREATE TABLE customers (customer_name VARCHAR, customer_id VARCHAR); CREATE TABLE mailshot_customers (customer_id VARCHAR)
Question: Show the names of customers who have at least 2 mailshots with outcome code 'Order'.
SQL: SELECT T2.customer_name FROM mailshot_customers AS T1 JOIN customers AS T2 ON T1.customer_id = T2.customer_id WHERE outcome_code = 'Order' GROUP BY T1.customer_id HAVING COUNT(*) >= 2