Select rows from a table if one of them matches with another table

Question

I have 3 tables:

• product
• movement
• movement_product

The product table has a field group_id (is the product's group).
The movement_product table has a field movement_id (matches with movement table) and product_id (matches with the product table).

I want to select all the movement products of a movement if one of them is from a specific group of products.

I tried the following SQL:

SELECT
    mp.*
FROM
    movement AS m,
    movement_product AS mp
WHERE
    m.id = mp.movement_id
    AND EXISTS (
        SELECT *
        FROM product p
        WHERE mp.product_id = p.id
        AND p.group_id = "48"
    )
GROUP BY mp.movement_id

But it is returning a list just with the products that are from that specific group (the 48 on group_id is just an example).

Answer 1

If I understand correctly, you can follow this logic. First, to get all the movements that qualify:

select distinct mp.movement_id
from movement_products mp
where exists (select 1
              from products p
              where p.id = mp.product_id and
                    p.group_id = 48
             );

To get the products in these movements, you can do:

select mp.*
from movement_products mp
where mp.movement_id in (select mp.movement_id
                         from movement_products mp
                         where exists (select 1
                                       from products p
                                       where p.id = mp.product_id and
                                       p.group_id = 48
                        );