Sql 两个一对多表之间的联接

我有这两个表，我必须编写此SQL查询（Microsoft Access）：

• 写一个查询，显示每一位售出任何书籍的作者的书名（图书编号）和销售量（订购数量）

我尝试过这个查询，但不起作用

SELECT authors.author_id, Count(orders.book_id) AS CountOfbook_id,
Sum(orders.quantity_ordered) AS SumOfquantity_ordered
FROM authors 
LEFT JOIN orders ON authors.book_id = orders.book_id
GROUP BY authors.author_id;

但它不起作用，因为它计算了从客户订单上取下的同一本书的许多倍。这个怎么样

select author,sum(CountOfbook_id), sum(SumOfquantity_ordered)
from (
    SELECT authors.author_id as author, Count(orders.book_id) AS CountOfbook_id,
    Sum(orders.quantity_ordered) AS SumOfquantity_ordered
    FROM authors 
    LEFT JOIN orders ON authors.book_id = orders.book_id
    GROUP BY authors.author_id,authors.book_id;)
group by author;

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你试过什么？它产生了什么结果/它与您想要的有什么不同？请阅读并接受答案我编写了我在底部尝试的查询SQL，Microsoft Access我尝试了，但我得到了同一作者两次，请参见：我已修改它