MySQL查询到每个组

Question

内计算百分比如何这个结果转换：

week,day,hour,branch,sales 
1,1,1,a,50 
1,1,1,b,50 
1,1,2,a,25 
1,1,2,b,75 

进入这个：

week,day,hour,branch,sales,percentage 
1,1,1,a,50,50% 
1,1,1,b,50,50% 
1,1,2,a,25,25% 
1,1,2,b,75,75% 

注意，百分比以每小时分组。换句话说，它不是所有销售额的百分比，而是每小时内的销售额。我曾尝试下面的查询，但是这给了我所有的销售百分比：

SELECT week,day,hour,branch,sales, 
(sales/(SELECT SUM(sales) FROM test))*100 AS Percentage 
FROM test 
GROUP BY week,day,hour,branch 

Answer 1

使用相关子查询：

SELECT week, day, hour, branch, sales, 
     (sales/(SELECT SUM(sales) 
       FROM test t2 
       WHERE t2.hour = t.hour and t2.week = t.week and t2.day = t.day 
      ) 
     ) * 100 AS Percentage 
FROM test t 
GROUP BY week, day, hour, branch;