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

select
    P.id,
    P.name,
    count(P.id) as matched_attr_count,
    count(PA.a_id) as total_attr_count
from
    product_attributes PA
    left join product P on P.id = PA.p_id and PA.a_id in (21,23,24)
group by
    PA.p_id
having
    matched_attr_count = total_attr_count;