题解 |
返回购买 prod_id 为 BR01 的产品的所有顾客的电子邮件（一）
https://www.nowcoder.com/practice/962b16554fbf4b99a87f4d68020c5bfb
select cust_email from OrderItems join Orders using (order_num) join Customers using(cust_id) where prod_id='BR01' ;
from t1 join t2 using (x)
优于
from t1 join t2 on t1.x = t2.x
优于
from t1,t2 where t1.x = t2.x ;
注意 using需要后面跟括号（即使单列）