Question

我有一张这样的表：

Votes (id, person, positive_vote, negative_vote)

我想按人分组，并按每个人的总票数排序。我知道如何获得一个组的单个列的总和，但是我无法弄清楚如何获得每个组的总和（总票数）。

这是我到目前为止所拥有的：

SELECT person, sum(positive_vote), sum(negative_vote) FROM Votes GROUP BY person;

Answer 1

尝试，

SELECT person, 
       sum(positive_vote) totalPositive, 
       sum(negative_vote) totalNegative,
       (sum(positive_vote) + sum(negative_vote)) totalVotes
FROM Votes 
GROUP BY person
-- HAVING (sum(positive_vote) + sum(negative_vote)) < 5

Answer 2

SELECT Z.person,Z.sum_pv,Z.sum_nv,Z.diff_sum_pv_nv
FROM
(SELECT person, sum(positive_vote) AS sum_pv, sum(negative_vote) sum_nv,sum(positive_vote) - sum(negative_vote) AS diff_sum_pv_nv
FROM Votes GROUP BY person)Z;

Answer 3

如果您想要每个人的总数，只需减去总和（或者如果您只想要总计数量的选票，则添加它们）：

SELECT person, sum(positive_vote), sum(negative_vote),
    SUM(positive_vote)-SUM(negative_vote)
FROM Votes 
GROUP BY person

注意我在这里减去了总和并且没有总结列本身的差异，因为我不知道你是如何在表中存储数据的，而NULL可以用数学做有趣的事情。

Answer 4

你的意思是positive_vote和negative_vote的总和吗？

SELECT 
  person, 
  SUM(positive_vote) AS positive_votes, 
  SUM(negative_vote) AS negative_votes,
  SUM(positive_vote + negative_vote) AS total_votes
FROM Votes GROUP BY person;

Answer 5

SELECT person, 
       sum(positive_vote) as totalPositive, 
       sum(negative_vote) as totalNegative,
       (sum(positive_vote + negative_vote)) as totalVotes
FROM Votes 
GROUP BY person

MySQL组由多列总和和每个组的总和组成

5 个答案: