Question

我有两个表，一个是订单，第二个是order_product，其中我必须找到订单数量，产品数量，totalamount对应商店使用商店ID我已经成功找到订单数量和产品数量但是我的totalamount不正确。

订单：

...........................
 order_id      or_total_amt
...........................
    1           10           
    2           10         
    3           10

order_product

.................................
 op_id  op_order_id  st_id
.................................
   1       1          1
   2       2          2
   3       3          1
   4       3          1

我想要低于输出但是我的totalamount值出错了它将会出现30，但是正确的值是20，我在右下方输出中提到过。

我想要的输出：

.........................................
 st_id    orders   product   totalmount
.........................................
   1         2        3          20
   2         1        1          10

我已经尝试过以下查询，它给出了30个值为totalamount的错误。

SELECT `op_st_id`,count(distinct orders.`order_id`)as orders,count(order_product.op_pr_id) as product
,sum(orders.or_total_amt) as totalamount from orders 
inner JOIN order_product on orders.order_id=order_product.op_order_id
group by `op_st_id`

Answer 1

SELECT
    `st_id`,
    count(DISTINCT orders.`order_id`) AS orders,
    count(order_product.op_id) AS product,
    count(DISTINCT orders.`order_id`)*(sum(orders.or_total_amt)/count(order_product.op_id)) AS totalamount
FROM
    orders
INNER JOIN order_product ON orders.order_id = order_product.op_order_id
GROUP BY
    `st_id`

如何在mysql中从内连接中获得正确的总和

1 个答案: