CREATE TABLE product (product_name VARCHAR, product_id VARCHAR)
CREATE TABLE problems (product_id VARCHAR)

How many problems does the product with the most problems have? List the number of the problems and product name.
SELECT COUNT(*), T1.product_name FROM product AS T1 JOIN problems AS T2 ON T1.product_id = T2.product_id GROUP BY T1.product_name ORDER BY COUNT(*) DESC LIMIT 1
SELECT COUNT(*), "T1"."product_name" FROM "product" AS "T1" JOIN "problems" AS "T2" ON "T1"."product_id" = "T2"."product_id" GROUP BY "T1"."product_name" ORDER BY COUNT(*) DESC NULLS LAST LIMIT 1