CREATE TABLE order_items (order_id VARCHAR2, product_id VARCHAR2)
CREATE TABLE customer_orders (order_id VARCHAR2, customer_id VARCHAR2)
CREATE TABLE products (product_name VARCHAR2, product_id VARCHAR2)

Find the names of products that were bought by at least two distinct customers.
SELECT DISTINCT T3.product_name FROM 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 GROUP BY T3.product_id HAVING COUNT(DISTINCT T1.customer_id) >= 2
SELECT DISTINCT "T3"."product_name" FROM "customer_orders" "T1" JOIN "order_items" "T2" ON "T1"."order_id" = "T2"."order_id" JOIN "products" "T3" ON "T2"."product_id" = "T3"."product_id" GROUP BY "T3"."product_id" HAVING COUNT(DISTINCT "T1"."customer_id") >= 2