SQL AVG在桌子上

Question

我有下表

我想获得每个prod_type_desc的平均价格，我有以下代码让我在这里，但不能弄明白其余的。

select * from (select price, prod_type_desc from products NATURAL JOIN producttypes NATURAL JOIN refproducttypes) as a

我尝试了select AVG(price), prod_type_desc from above，但这不起作用。

Answer 1

您需要在GROUP BY

上使用product_type_desc

select prod_type_desc, avg(price) from products group by prod_type_desc

Answer 2

此声明应该有效，

select prod_type_price, avg(price) from products group by prod_type_price