Question

我有以下查询

SELECT COUNT( DISTINCT id ) AS `total` , YEAR( created_date ) AS `memberYear`
FROM `users` AS `u`
WHERE (
role_id =2
AND is_deleted =0
AND is_trashed =0
)
GROUP BY `memberYear`

通过这个查询，我得到了这样的记录

total   memberYear
 10        2012 
 12        2013 
 2         2014

现在我需要记录上一年的总和

total   memberYear sumTotal
10        2012       10
12        2013       22
2         2014       24

我怎样才能获得总和的总和？任何帮助将不胜感激。

Answer 1

如果您使用存储过程或使用嵌套选择，则只能使用mysql执行此操作，但我不建议使用它。由于您使用PHP并且已经有查询响应，只需将当前年份值添加到上一个：

$sumTotal=0;
while ($row=mysql_fetch_array($res)){
    $sumTotal+=$row["total"];
}

Answer 2

请试试这个：

SELECT COUNT( DISTINCT id ) AS `total` , YEAR( created_date ) AS `memberYear`,
@running_total := @running_total + COUNT(DISTINCT id) AS total
FROM `users` AS `u`
, (SELECT @running_total := 0) var_init_subquery
WHERE (
role_id =2
AND is_deleted =0
AND is_trashed =0
)
GROUP BY `memberYear`

Answer 3

您正在寻找累计金额。不幸的是，mysql还不支持窗口函数，这使得这些事情变得非常容易。一种方法是使用theta self join，如：

SELECT X.memberYear, sum(y.total)
FROM (
    SELECT COUNT( DISTINCT id ) AS `total` , YEAR( created_date ) AS `memberYear`
    FROM `users` AS u
    WHERE role_id =2
      AND is_deleted =0
      AND is_trashed =0
    GROUP BY memberYear
) AS x 
JOIN (
    SELECT COUNT( DISTINCT id ) AS `total` , YEAR( created_date ) AS `memberYear`
    FROM `users` AS `u`
    WHERE role_id =2
      AND is_deleted =0
      AND is_trashed =0
    GROUP BY `memberYear`
) y
   on y.memberyear <= x.memberyear
group by X.memberYear

这是未经测试的，因此可能存在一些错误。

如何获得上一年的总和与下一年的总和

3 个答案: