Question: Show the names of products that are in at least two events.
Schema: create table products (product_name varchar, product_id varchar, PRIMARY KEY (product_name)); create table products_in_events (product_id varchar, PRIMARY KEY (product_id))
SQL: select t1.product_name from products as t1 join products_in_events as t2 on t1.product_id = t2.product_id group by t1.product_name having count(*) >= 2