【笔记】oracle using

oracle using

在oracle中，using用于简化连接查询，只有当查询是等值连接和连接中的列必须具有相同的名称与数据类型时，才能使用using关键字进行简化

比如原来是

select s.user_id as user_id ,
sum(s.quantity * p.price) as spending
from Sales s join Product p on s.product_id = p.product_id
group by s.user_id
order by sum(s.quantity * p.price) desc,s.user_id asc

可以写成

select s.user_id as user_id ,
sum(s.quantity * p.price) as spending
from Sales s join Product p USING(product_id)
group by s.user_id
order by sum(s.quantity * p.price) desc,s.user_id asc