Question

我有一个关于MySQL的问题。

我收到了以下表格：

Invoices
invoices_ordermapping
invoices_positions

发票：

id | userid | state
1, 10, 1

invoices_ordermapping

id | invoiceid | orderid
1, 1, Order12
2, 1, Order13

invoices_positions

id | invoiceid | value | text
1, 1, 21, Example
2, 1, 18.9, Example 2

现在我想将已分配的订单发送到发票（Order12，Order13）和总和（价值总和）。

这是我期望的结果：

Invoiceid | Orders | Sum
1, Order12, Order13, 39.9

我正在使用这个MySQL-Query：

SELECT group_concat(DISTINCT orderid ORDER BY orderid SEPARATOR ", ") AS orderid, 
       SUM(ip.total) as value
FROM tbl_invoices as a
LEFT JOIN tbl_invoices_ordermapping as oi ON oi.invoiceid = a.id 
LEFT JOIN tbl_invoices_positions as ip on ip.invoiceid = oi.invoiceid          
GROUP BY oi.invoiceid
ORDER BY oi.invoiceid

不幸的是我得到了这个结果：

Orderid: Order12, Order12, Order13, Order13
Value: 119.69999885559082

我在这里做错了什么？

Answer 1

我认为您需要以下内容：

SELECT a.id AS InvoiceId, Orders, `Sum`
FROM Invoices as a
LEFT JOIN (SELECT invoiceid,
                  GROUP_CONCAT(DISTINCT orderid 
                               ORDER BY orderid SEPARATOR ', ') AS Orders
           FROM Invoices_ordermapping 
           GROUP BY invoiceid ) AS oi ON oi.invoiceid = a.id
LEFT JOIN (SELECT invoiceid, SUM(`value`) as `Sum`
           FROM Invoices_positions
           GROUP BY invoiceid) AS ip ON ip.invoiceid = a.id
ORDER BY a.id

您的查询的问题是LEFT JOIN重复Invoices_positions行，因此，SUM计算在表的相同行的多次出现时。

您需要先为Invoices_ordermapping和Invoices_positions表执行聚合，然后加入Invoices表。

Fiddle Demo here

具有GROUP CONCAT和LEFT JOIN的行的SUM

1 个答案: