我想在sql结果的每一行上显示性别百分比。我的数据如下:
CREATE TABLE Results
( employeeId varchar(45) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci DEFAULT NULL
, Employee_Name varchar(228) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci DEFAULT NULL
, gender varchar(1) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci DEFAULT NULL
, Citizenship varchar(100) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=latin1;
insert into Results values
(1,'A','M','India'),
(2,'B','F','India'),
(4,'D','F','France'),
(3,'C','F','Lebanon'),
(5,'E','M','Sri Lanka');
通过使用
,按性别计数的百分比为 M 40,F 60select gender, round(count(gender) * 100/sum(count(gender)) over (),2) percentage
from Results
group
by gender;
此查询将返回M&F的结果,但我希望对表中的每一行重复该百分比,
employeeId EmployeeName gender Citizenship Percentage
1 A M India 40
2 B F India 60
4 D F France 60
3 C F Lebanon 60
5 E M Sri Lanka 40
我该怎么做?
答案 0 :(得分:2)
不需要group by
或任何联接。
仅使用COUNT()
窗口功能:
select *,
round(100.0 * count(*) over (partition by gender) / count(*) over (), 2) percentage
from Results
order by employeeId
请参见demo。
结果:
> employeeId | Employee_Name | gender | Citizenship | percentage
> :--------- | :------------ | :----- | :---------- | ---------:
> 1 | A | M | India | 40.00
> 2 | B | F | India | 60.00
> 3 | C | F | Lebanon | 60.00
> 4 | D | F | France | 60.00
> 5 | E | M | Sri Lanka | 40.00
答案 1 :(得分:1)
我只需要加入一个子查询即可找到每种性别的百分比:
SELECT
t1.employeeId,
t1.EmployeeName,
t1.gender,
t1.Citizenship,
t2.pct AS Percentage
FROM yourTable t1
INNER JOIN
(
SELECT gender, ROUND(100.0 * COUNT(*) / SUM(COUNT(*)) OVER (), 2) AS pct
FROM yourTable
GROUP BY gender
) t2
ON t1.gender = t2.gender;