Table schema:
CREATE TABLE order_items (order_id VARCHAR, product_id VARCHAR); CREATE TABLE customers (customer_name VARCHAR, customer_id VARCHAR); CREATE TABLE customer_orders (customer_id VARCHAR, order_id VARCHAR)

Question: Find the names of customers who have bought by at least three distinct products.
SQL: SELECT DISTINCT T1.customer_name FROM customers AS T1 JOIN customer_orders AS T2 ON T1.customer_id = T2.customer_id JOIN order_items AS T3 ON T2.order_id = T3.order_id GROUP BY T1.customer_id HAVING COUNT(DISTINCT T3.product_id) >= 3