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

If you pretend that your filter is in a table:

select * 
from product p
where not exists (
    select 1
    from attributes a
    where a.product_id = p.product_id
    and not exists(
        select 1
        from filter f
        where f.id_attribute = a.id_attribute))

If it was in a constructed query:

select * 
from product p
where not exists (
    select 1
    from attributes a
    where a.product_id = p.product_id
    and attribute_id not in (<list>))

This is off the top of my head, so may have typos.

Answer 2

Assuming your product table is called Product and the ID column in that table is just called Id:

SELECT * from Product p where p.Id IN 
  (Select id_product from ProductAttributes where id_attribute in (21, 23, 24))

Answer 3

This should return only those id's where all attributes for each id are completely contained within the list:

select attribute_match.id_product from
 (select id_product, count(*) c from attributes
  where id_attribute in (21, 10, 25)
  group by id_product) attribute_match,
 (select id_product, count(*) c_count from attributes
  group by id_product) attribute_total
where attribute_match.id_product = attribute_total.id_product
      and attribute_match.c = attribute_total.c

Answer 4

Based on your insight guys, I optimized it even further and used only 1 COUNT statement like this:

SELECT * ,COUNT(p.product_id) AS c FROM product_attribute pa 
LEFT JOIN products p ON pa.product_id = p.product_id AND pa.attribute_id NOT IN ($filter_list)
GROUP BY pa.product_id
HAVING c=0

Does it work ? :)

Edit:
That code doesn't return the product's name or other fields it might have. This is the correct one:

SELECT * ,COUNT(pa.product_id ) AS c FROM products p
LEFT JOIN product_attribute pa ON pa.product_id = p.product_id AND pa.attribute_id NOT IN ($filter)
GROUP BY p.product_id
HAVING c=0

Answer 5

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.

Answer 6

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;