mysql - Tricky sql query for popularity

Question

ProductId | BrandId | Views
    1         | 1       | 3
    2         | 1       | 2
    3         | 2       | 3
    4         | 2       | 4

需要编写 sql 查询来返回这个值:

BrandId | ViewsSummary
1       | 5
2       | 7

请问，怎么做？

Answer 1

这并不“棘手”——您只是想用适当的 aggregate function 将您的结果分组 :

SELECT BrandId, SUM(Views) AS ViewsSummary FROM my_table GROUP BY BrandId

查看 sqlfiddle .