Question

我使用此查询：

SELECT 
      `o_p`.`id`, 
      `o`.`user_id` AS `buyer`,
      `product_number` 
FROM `order_products` `o_p` 
LEFT JOIN `order` `o` ON o.id=o_p.id 
WHERE (`o_p`.`product_id`='5') AND (`o`.`pay_status`=1)

然后我得到了这个结果：

id buyer product_number

20 7     13

26 7     10

27 19    10

或者您可以在link

看到结果

但是我想计算买家的预期数字为2的数字，以及期望为“33”的product_number总数。

我该如何修复查询。

Answer 1

使用count(distinct user_id)代表唯一买方，sum(product_number)代表product_number

select count(distinct o.user_id) as buyer_number,
sum(product_number) as product_number_total
from order_products o_p 
left join order o on o.id=o_p.id 
where (o_p.product_id='5') and (o.pay_status=1)

Answer 2

使用COUNT(o.user_id)表示唯一买家的数量，使用SUM(product_number)表示product_number的总数。最后，GROUP BY o.user_id。

SELECT
      COUNT(o.user_id) AS buyer_number,
      SUM(product_number) AS product_number_total
FROM order_products o_p 
LEFT JOIN order o ON o.id=o_p.id 
WHERE (o_p.product_id='5') AND (o.pay_status=1)
GROUP BY o.user_id

MySQL在单个查询中获取COUNT和SUM

2 个答案: