mysql 数据库 多表 复合 查询

Question

一共有3个表,
goods表,有3个字段: id (int,PK) , price (float), name (varchar(20))
buyer表,有2个字段: id(int,PK) ,name (varchar(20))
buyRecord表,有3个字段:id(int PK), buyerId(int,FK) , goodsId(int,FK)
问题:
如何用一句或多句语句查询出buyer表中id为0的用户的消费总金额?

Answer 1

select sum(good.price) from good inner join buyRecord on (good.id = buyRecord.goodsId) where buyRecord.buyerId = 0;