题解 |子查询，多表

#where查询
select o1.cust_id,o1.order_date from Orders as o1 ,OrderItems as o2
where o2.prod_id ="BR01" and o1.order_num = o2.order_num order by 
order_date;

#子查询
select o1.cust_id,o1.order_date from Orders as o1 where order_num in
(select order_num from OrderItems where prod_id ="BR01") order by 
order_date;