Question

I have tables like

products            product_attributes
==================  ========================================
| id | name      |  | id | product_id | attribute | value  |
==================  ========================================
| 1  | product 1 |  | 1  | 1          | min       | 2    |
| 2  | product 2 |  | 2  | 1          | max       | 5    |
| 3  | product 3 |  | 3  | 2          | min       | 10   |
| 3  | product 3 |  | 4  | 2          | max       | 15   |
| .. | ...       |  | 5  | 3          | min       | 1    |
==================  | 6  | 3          | max       | 100  |
                    | .. | ...        | ...       | ...  |
                    ========================================

I want to get all the products that fall within a range
I can successfully get a list of the ids that fall with-in the range using

SELECT p.id 
  FROM `products` p INNER JOIN `product_attributes` AS pa ON p.id = pa.product_id   
  WHERE  pa.`min` <= 5 AND  pa.`max` >= 5 GROUP BY p.id

This gives me a list of the ids that i need.
What i can not get to work is to get a TOTAL count of the ids instead of a list so i can not use the group by and then when i do that it messes up the count.

Is the only way to do this is by using the select above in a subselect and counting the
results?

Thanks

Answer 1

Given the structure above, where min and max are on different rows, I would use this:

select count(id) from (
  select p.id
  from
    `products` p INNER JOIN `product_attributes` AS pa
    ON p.id = pa.product_id
  where (pa.attribute='min' and pa.value>=5) OR
        (pa.attribute='max' and pa.value<=5)
  group by p.id
  having count(*)=2
) s