mysql - MySQL查询按ID百分比

我有一个这样的表：

"Order1", "Product1", "3"
"Order1", "product2", "5"
"Order2", "product1", "2"

依此类推，我想要一个输出类似以下内容的查询：

"Order1", "Product1", "3/8"
"Order1", "product2", "5/8"
"Order2", "product1", "2/n"

8是每个订单上产品总数的总和。

有任何想法吗？谢谢！

最佳答案

这可以为您工作：

SELECT s.ordernr
      ,p.product
      ,CONCAT(p.quantity, '/', sum(s.quantity) AS percentage
FROM yourtable s
LEFT JOIN yourtable p ON p.orderid = s.oerderid
GROUP BY s.ordernr
ORDER BY s.ordernr;