题解 | #返回顾客名称和相关订单号#

#where查询
select cust_name,order_num
from Customers,Orders
where Customers.cust_id=Orders.cust_id
order by cust_name;
#自然连接
select cust_name,order_num
from Customers 
natural join Orders
order by cust_name
#内连接
select cust_name,order_num
from Customers 
inner join Orders
on Customers.cust_id=Orders.cust_id
order by cust_name
#左连接
select cust_name,order_num
from Customers 
left join Orders
on Customers.cust_id=Orders.cust_id
order by cust_name