CREATE TABLE problems (product_id VARCHAR); CREATE TABLE product (product_id VARCHAR)
SELECT COUNT(*), T2.product_id FROM problems AS T1 JOIN product AS T2 ON T1.product_id = T2.product_id GROUP BY T2.product_id
สินค้าแต่ละชิ้นที่มีปัญหามีจำนวนปัญหาและรหัสสินค้าเท่าไร?
For each product which has problems, what are the number of problems and the product id?