Show the names of products and the number of events they are in.
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))
select t1.product_name, count(*) from products as t1 join products_in_events as t2 on t1.product_id = t2.product_id group by t1.product_name