Selecting against subsets of a list in MySQL

Question

I\'m quite a begginer and I have two tables: \"product\" and \"product attributes\".

Here\'s some imaginary data (the actual stuff involves more tables )

Pr

Answer 1

Until MySQL supports the EXCEPT query combination,

SELECT product_id
  FROM attributes
  WHERE product_id NOT IN (
       SELECT product_id
         FROM attributes 
         WHERE attribute_id NOT IN (21, 23, 24)
     )
  GROUP BY product_id
UNION
SELECT id 
  FROM products AS p
  LEFT JOIN attributes AS a
    ON p.id = a.product_id
  WHERE a.product_id IS NULL

If you wish to have only the products with all the given attributes, add a HAVING COUNT(*)=n clause to the first outer query, where 'n' is the length of the attribute list.