mysql query return null row

i want to execute this query but it return null row when the table empty. it's working when SUM(products.sale_price)/COUNT(orders.id) AS avg_price_rang is not in the query

SELECT
    products.brand_id,
    (SELECT
        category_brands.name
     FROM
        category_brands
     WHERE
        category_brands.id=products.brand_id
    ) AS brand,
    products.material_id,
    (SELECT
        category_materials.material
     FROM
        category_materials
     WHERE
        category_materials.id=products.material_id
    ) AS material,
    orders.color_code,
    SUM(products.sale_price)/COUNT(orders.id) AS avg_price_rang
FROM
    orders
INNER JOIN
    products
ON
    orders.prodcut_id = products.id