Missing product

missing_inventory.sql

select 
    o.order_id as 'NEG order',
    d.client_reference as 'Order number',
    o.status as 'Order status',
    p.name as 'Product name',
    p.sku as 'SKU',
    p.upc as 'Barcode',
    SUM(i.quantity) as 'Order calls for',
    SUM(IFNULL(y.available, 0)) as 'Available',
    SUM(IFNULL(y.allocated, 0)) as 'Allocated to other orders',
    SUM(IFNULL(y.quantity, 0)) as 'Overall Quantity',
    d.order_date
from
    orders o
        inner join
    order_details d ON o.order_id = d.order_id
        inner join
    order_inventory i ON o.order_id = i.order_id
        inner join
    nep_products p ON i.product_id = p.id
        left outer join
    inventory y ON y.product_id = i.product_id
where
    o.client_id = 'CLIENT_ID'
        and status = 'Saved'
group by o.order_id , p.sku
order by o.order_id , p.sku