MySQL查询结果的总和

Question

我在表格中有一个名为“trail”的表我有3列名为“id”，“name”和“grading”。

我有以下查询，它根据id给出了特定路径名称的最后5行。这很有效，但现在我需要在评分栏中得到5个结果的总和吗？

SELECT * FROM `trails` WHERE `name` = "Free Flow" ORDER BY `id` DESC LIMIT 5

Answer 1

SELECT sum(`grading`)
FROM
  (SELECT *
   FROM `trails`
   WHERE `name` = "Free Flow"
   ORDER BY `id` DESC LIMIT 5) AS TEMP;

Answer 2

您可以使用此查询来获取特定列的总和

SELECT SUM(originalOfferSize)
FROM `ActiveListings`
WHERE `originalOfferSize` = 4000000
ORDER BY `listingId` DESC LIMIT 5