Question

我有两个表，一个是订单，第二个是 order_product ，其中我必须找到与买家ID对应的订单总数和产品总数。我已经找到正确的产品总数，但我无法做到找出订单总数。下面是我的表结构。

订单

........................
order_id   or_buyer_id
.......................
  1           21

order_product

.................................
op_id  op_order_id  op_buyer_id
.................................
  1       1          21
  2       1          21

我想要此输出，我已经应用了以下查询，但它返回正确的产品价值和错误的订单价值。

..................................
 or_buyer_id    orders    product
.................................
    21            1        2

但我从下面的查询中得到这个

...............................
or_buyer_id  orders  product
...............................
   21         2       2

我的疑问：

SELECT o.`or_buyer_id`, count(o.`or_buyer_id`) as orders, count(op.op_buyer_id) as product FROM `orders` as o inner JOIN order_product as op on op.op_order_id=o.order_id and o.or_buyer_id = op.op_buyer_id group by o.`or_buyer_id`

Answer 1

查看以下链接说明如何完成此操作：

带有GROUP BY子句的MySQL INNER JOIN

http://www.mysqltutorial.org/mysql-inner-join.aspx

SELECT 
    T1.orderNumber,
    status,
    SUM(quantityOrdered * priceEach) total
FROM
    orders AS T1
        INNER JOIN
    orderdetails AS T2 ON T1.orderNumber = T2.orderNumber
GROUP BY orderNumber;

所以你的查询的答案如下：

SELECT 
    ord.or_buyer_id,
    count(DISTINCT ord.or_buyer_id) as orders,
    count(op.op_id) as product 
FROM 
    orders as ord
inner JOIN 
    order_product as op  
ON 
    op.op_order_id=ord.order_id 
and 
    ord.or_buyer_id = op.op_buyer_id
group by 
    ord.or_buyer_id

Answer 2

您只需选择or_buyer_id并按其分组，并添加额外的加入条件以匹配两个表之间的or_buyer_id：

SELECT o.`or_buyer_id`,
  count(DISTINCT o.`or_buyer_id`) as orders,
  count(op.op_id) as product 
FROM `orders` as o
inner JOIN order_product as op  on op.op_order_id=o.order_id 
                               and o.or_buyer_id = op.op_buyer_id
group by o.`or_buyer_id`;

demo

| or_buyer_id | orders | product |
|-------------|--------|---------|
|          21 |      1 |       2 |

如何在mysql中使用内部联接使用多个组

2 个答案: