id номер записи
prod_id номер продукта
id_cat номер категории
attrs_id_val занчение свойства (красный 1, белый 2, индезит 4 и т.п.)
id_attr номер свойства в таблице свойства
SELECT
attrs_id_val,
count(attrs_id_val)
FROM prodfltrsattrsvalues
where cat_id = 34
GROUP BY attrs_id_val
SELECT
product_id
FROM prodfltrsattrsvalues
where cat_id = 34 and attrs_id_val IN(40 ,136,116)
GROUP BY product_id
HAVING COUNT(*) =3
select
m.name,
count(*) as goods_count
from goods as g
inner join manufacturers as m
on g.manufacturer = m.id
where category = 1
group by m.name;