SQL queries

--  a- list of clients, which have an order with order_sum > 50 
select c.client_id, c.client_name from Clients as c
inner join Orders as o on o.client_id = c.client_id
where o.order_sum > 50

--  b- clients, whose total sum of orders exceeds 100
Select * from
	(select c.client_id, c.client_name, SUM(o.order_sum) as total from Clients as c
	inner join Orders as o on o.client_id = c.client_id
	GROUP BY c.client_id) as t
where total > 100