Question

我当前的查询：

SELECT Delaytype, SUM('Delayhours') as cnt 
FROM delays 
GROUP BY Delaytype;

如何将cnt作为百分比而不是总出现次数的总和？

Answer 1

我想这就是你想要的：

SELECT Delaytype, SUM(Delayhours) / (SELECT SUM(Delayhours) FROM delays) * 100 as cntper 
FROM delays 
GROUP BY Delaytype

或者，如果您的数据库支持子选择，这应该更有效：

SELECT Delaytype, cnt / SUM(cnt) * 100 FROM (
  SELECT Delaytype, SUM(Delayhours) as cnt
  FROM delays 
  GROUP BY Delaytype
) AS GroupedDelays

Answer 2

一种方法是交叉加入总和：

SELECT     d.Delaytype, SUM(d.Delayhours)/total_delay as pct
FROM       delays 
CROSS JOIN (SELECT SUM(Delayhours) AS total_delay
            FROM   delays) t
GROUP BY   d.Delaytype;

SQL为百分比而不是总数

2 个答案: