从连接表中选择所有和AVG

Question

请你能帮得到以下所述情况查询：

1 TABLE: shops: id | name | is_locked | 
2 TABLE: products: id | name | price  | shop_id 
3 TABLE: rates: id | rate | is_accepted | shop_id 

我有3代表的商店，店里的产品和价格。现在我想对所有属于未锁定商店的产品进行分类，并按平均接受的商店价格进行排序。这个查询应该如何？

Answer 1

你可以试试这个：

select p.name, p.price, AVG(r.rate) 
from shops s, products p, rates r 
Where s.is_locked <> 1 and 
     s.id = p.shop_id and 
     s.id = r.shop_id and 
     p.shop_id = r.shop_id 
group by p.id 
order by AVG(r.rate)