Question

假设一个小镇正在举行选举，每个公民都可以根据自己的意愿多次投票，但他们投票的次数越多，他们投票的次数越多，他们就不能进行重复投票。

Voter   Vote
---------------
Jane    Jane
Howard  Jane
John    Howard
John    Howard
Jane    John
Sara    Howard

您如何在SQL查询中确定获胜者是谁？

我是基本用户，所以我得到的只是

SELECT  
    vote, COUNT( vote) 
FROM 
    table1 
GROUP BY
    vote

这并不考虑重复或分割投票。

帮助？

SQLFiddle

Answer 1

您可以使用动态创建的表

 select vote, count(*) 
 from 
     (select distinct voter, vote 
      from table1) as t
 group by vote

Answer 2

SELECT V.vote, SUM(W.weight) AS votes
FROM 
(
SELECT  voter, CAST(1 AS FLOAT) / COUNT(vote) AS weight
FROM table1 
group by voter
) W
JOIN
(
SELECT DISTINCT vote, voter
FROM table1 
) V ON W.voter = V.voter
GROUP BY V.vote

Answer 3

试试这个：

select vote, sum(1 / votes) as result from 
(SELECT voter, count(*) as votes from Table1 group by voter) votecount 
INNER JOIN Table1 on votecount.voter = Table1.voter
group by vote
order by result desc

这会以一个选民可以给出2/3和1/3票数的方式处理重复数据

修改通过

添加订单

Answer 4

您可以使用不同的选民和投票组合来删除重复投票

SELECT vote,COUNT(distinct voter) FROM table1 group by vote

Answer 5

您可以通过子查询确定每个选民投票的适当权重。

win32com.client

http://sqlfiddle.com/#!9/9e569/48

SQL计数和重复

5 个答案: