Question

我应该开始说我正在使用postgresql。我有四个表，customer_orders，payment和clearinghouse_orders。 Customer_orders是支付和清算所订单的一对多。

当我使用此查询时，我的总数是正确的：

SELECT mailers.mail_date, SUM(cho.remit) AS remits
FROM mailers
RIGHT JOIN customer_orders co
ON mailers.id = co.mailer_id
LEFT JOIN clearinghouse_orders cho
ON co.id = cho.customer_order_id
GROUP BY mailers.mail_date

汇款总额是完美的。当我添加付款表时，佣金会增加。我怀疑当我添加付款时，它开始计算两次付款的两次付款。以下是需要更正的代码：

SELECT mailers.mail_date, SUM(cho.remit) AS remits, SUM(p.payment_amt) AS    payments
FROM mailers
RIGHT JOIN customer_orders co
ON mailers.id = co.mailer_id
LEFT JOIN clearinghouse_orders cho
ON co.id = cho.customer_order_id
LEFT JOIN payments p
ON co.id = p.customer_order_id
GROUP BY mailers.mail_date

我是SQL的初学者，所以请放轻松我。我们将非常感谢您提供的任何帮助。

Answer 1

如果您的理论是正确的，那么删除重复付款行的简单子查询应解决这个问题......

SELECT mailers.mail_date, SUM(cho.remit) AS remits, SUM(p.payment_amt) AS    payments
FROM mailers
RIGHT JOIN customer_orders co
ON mailers.id = co.mailer_id
LEFT JOIN clearinghouse_orders cho
ON co.id = cho.customer_order_id
LEFT JOIN
    (
        select
            customer_order_id,
            sum(payment_amt) as payment_amt
        from
            payments
        group by
            customer_order_id
    ) as p
ON co.id = p.customer_order_id
GROUP BY mailers.mail_date

添加第二个联接时，金额更改并且不正确

1 个答案: