在 PostgreSQL 中使用 INNER JOIN 时出错？

Question

由于我是 PostgreSQL 新手，所以我使用 PostgreSQL sample database 来学习和练习 PostgreSQL。我的问题陈述是找到在 4 月 10 日至 13 日期间租用电影的前 15 名最高消费客户的付款？我的查询如下：

SELECT customer.first_name,payment.amount
FROM customer
  INNER JOIN payment ON customer.customer_id = payment.customer_id
WHERE customer_id IN (SELECT customer_id 
                      FROM (
                        SELECT customer_id, SUM(amount)
                        FROM payment
                        WHERE extract(month from payment_date) = 4
                        AND extract(day from payment_date) BETWEEN 10 AND 13
                        GROUP BY customer_id
                        HAVING SUM(amount) > 5
                        ORDER BY SUM(amount) DESC
                        LIMIT 15
                      ) AS top_fifteen);

我收到以下错误：

relation "customer" does not exist

我不确定为什么我会在这里遇到这个异常，有人可以帮我解决这个问题吗？任何线索都受到高度赞赏。

Answer 1

使用如下表别名并尝试

SELECT c.first_name,p.amount
FROM customer c
INNER JOIN payment p
ON c.customer_id = p.customer_id
WHERE c.customer_id IN 
(
SELECT customer_id FROM 
    (
SELECT  customer_id, SUM(amount)
FROM payment
WHERE extract(month from payment_date) = 4
AND extract(day from payment_date) BETWEEN 10 AND 13
GROUP BY customer_id
HAVING SUM(amount) > 5
ORDER BY SUM(amount) DESC
LIMIT 15) AS top_fifteen);

我将您的查询改写如下

select * from
 (
 select  c.first_name,c.last_name,
 sum(amount) as pay_amount,
 count(p.customer_id) pay_num from payment p
 inner join Customer c on  p.customer_id=c.customer_id
     where extract(month from p.payment_date) = 4
AND extract(day from p.payment_date) BETWEEN 10 AND 13
 group by c.first_name,c.last_name,p.customer_id
 ) T 
 order by pay_amount desc
 Limit 15