Jak zahrnout hodnoty NULL do dotazu pomocí funkce Outer Join a Group By

Ve vašem dotazu pomocí count došlo k malé chybě. Funguje to.

select count(ui.item_id) as total, in.item_desc
from   item_name `in`
       left join user_items ui on ui.item_id = in.item_id
                                        and ui.user_id in (127, 128)
group by
       in.item_desc
order by total desc