prak databae

--1
select categories.*,items.* from items inner join categories on items.category_id=categories.category_id order by categories.category_id asc

--2
select suppliers.*, items.name from suppliers inner join items
on suppliers.supplier_id = items.supplier_id

--3
select items.*, categories.*, suppliers.* from items
inner join categories on categories.category_id = items.category_id
 inner join suppliers on suppliers.supplier_id = items.supplier_id
--4
select items.item_id, items.name,  items.stok, categories.explanation from items
 inner join categories on categories.category_id = items.category_id
 where stok>35 order by items.category_id asc
--5
select suppliers.supplier_id,
suppliers.name,suppliers.address, sum(items.stok) from suppliers
 inner join items on suppliers.supplier_id = items.supplier_id
 group by suppliers.supplier_id, suppliers.name, suppliers.address
--6
select suppliers.supplier_id,
suppliers.name,suppliers.address,  sum(items.purchasing_price * items.stok)
from suppliers inner join items on
suppliers.supplier_id = items.supplier_id
group by suppliers.supplier_id,
suppliers.name,suppliers.address

--7
select purchases.*, customers.* from purchases
inner join customers on customers.customer_id = purchases.customer_id
order by date desc

--8
select purchases.*, items.name from purchases
inner join purchase_items on purchases.purchase_id = purchase_items.purchase_id
inner join items on items.item_id = purchase_items.item_id
--9