Database: department_store_minus_1_0
Question: What are the distinct names of customers who have purchased a keyboard?
SQL: select distinct t1.customer_name from customers_customer_orders as t1 join order_items as t2 on t1.order_id = t2.order_id join products as t3 on t2.product_id = t3.product_id where t3.product_name = 'keyboard'