SQL计算运行

Question

我在我的Access数据库中运行SQL查询以累积我在每条记录之后运行的距离。

我用下面的代码来计算运行总计：

SELECT a.run, a.year, a.date, a.distance, round((SELECT SUM(b.distance) 
         FROM vwAllCast b 
         WHERE b.run <= a.run),1) AS AccDistance 
FROM vwAllCast AS a 
ORDER BY a.run DESC; 

此代码返回所有的记录总结在AccDistance所有距离。现在，我想每年都重新进行一次积累。有没有人有一个想法如何实现？

Answer 1

一样的Piyush说，我觉得这样的事情应该工作：

SELECT a.run, a.year, a.date, a.distance, round((SELECT SUM(b.distance) 
         FROM vwAllCast b 
         WHERE b.run <= a.run and a.year = b.year),1) AS AccDistance 
FROM vwAllCast AS a 
ORDER BY a.run DESC; 

Answer 2

自由可能比相关子查询更快加入+组

SELECT a.run, a.year, a.date, a.distance, SUM(b.distance) 
FROM vwAllCast AS a 
JOIN vwAllCast b on b.run <= a.run AND b.year = a.year 
GROUP BY a.run, a.year, a.date, a.distance 
ORDER BY a.run DESC