我正在尝试编写一个sql来计算以下输入中每个组的运行总数。只是想知道如何使用mysql来实现它。我知道如何在常规sql中使用分析函数而不是mysql。你能谈谈你对如何实施它的想法吗。
sql小提琴：http://sqlfiddle.com/#!9/59366d/19年
sql使用窗口函数：

SELECT e.Id,
       SUM( e.Salary ) OVER( PARTITION BY e.Id ORDER BY e.Month  ) AS cumm_sal
  FROM Employee e 
LEFT JOIN
       (
          SELECT Id,MAX(Month) AS maxmonth
            FROM Employee
          GROUP BY Id
        ) emax
    ON e.Id = emax.Id
WHERE e.Month != emax.maxmonth
ORDER BY e.Id,e.Month DESC;

输入：

Create table Employee (Id int, Month int, Salary int);

insert into Employee (Id, Month, Salary) values ('1', '1', '20');
insert into Employee (Id, Month, Salary) values ('2', '1', '20');
insert into Employee (Id, Month, Salary) values ('1', '2', '30');
insert into Employee (Id, Month, Salary) values ('2', '2', '30');
insert into Employee (Id, Month, Salary) values ('3', '2', '40');
insert into Employee (Id, Month, Salary) values ('1', '3', '40');
insert into Employee (Id, Month, Salary) values ('3', '3', '60');
insert into Employee (Id, Month, Salary) values ('1', '4', '60');
insert into Employee (Id, Month, Salary) values ('3', '4', '70');

输出：

| Id | Month | Salary |
|----|-------|--------|
| 1  | 3     | 90     |
| 1  | 2     | 50     |
| 1  | 1     | 20     |
| 2  | 1     | 20     |
| 3  | 3     | 100    |
| 3  | 2     | 40     |