select distinct b.item_category as Category,
ifnull(sum(case when dayofweek(a.order_date) = 2 then a.quantity end),0) Monday,
ifnull(sum(case when dayofweek(a.order_date) = 3 then a.quantity end),0) Tuesday,
ifnull(sum(case when dayofweek(a.order_date) = 4 then a.quantity end),0) Wednesday,
ifnull(sum(case when dayofweek(a.order_date) = 5 then a.quantity end),0) Thursday,
ifnull(sum(case when dayofweek(a.order_date) = 6 then a.quantity end),0) Friday,
ifnull(sum(case when dayofweek(a.order_date) = 7 then a.quantity end),0) Saturday,
ifnull(sum(case when dayofweek(a.order_date) = 1 then a.quantity end),0) Sunday
from Orders a right join Items b
on a.item_id = b.item_id
group by Category
order by Category
