MySQL的使用GROUP BY和SUM

Question

排名我有一個點表與一些列的是：

| user_id | points | 
-------------------- 
| 1  | 10 | 
| 5  | 10 | 
| 5  | 50 | 
| 3  | 15 | 
| 3  | 10 | 

我想獲得排名的與MySQL每個用戶。

我看到這篇文章MySQL get row position in ORDER BY但它沒有SUM，我不能讓它與SUM一起工作。

我希望能夠得到給定user_id的排名。

在此先感謝您的幫助！

Answer 1

提醒OP的問題：

我希望能夠得到一個給定的user_id軍銜。

爲了在實際執行操作@rank你有用戶的另一個派生表（是的，它是低效的，這就是爲什麼它是最好不要在MySQL處理此）：

SELECT * FROM (
    SELECT s.*, @rank := @rank + 1 rank FROM (
    SELECT user_id, sum(points) TotalPoints FROM t 
    GROUP BY user_id 
) s, (SELECT @rank := 0) init 
    ORDER BY TotalPoints DESC 
) r 
WHERE user_id = 3 

輸出

| USER_ID | TOTALPOINTS | RANK | 
|---------|-------------|------| 
|  3 |   25 | 2 | 

的方法基本上是：

1. 獲取的總額分每用戶
2. 排序的總積分排名
3. 過濾器，一旦你有秩（否則，排名將受到損害）

小提琴here。

Answer 2

試試這個::

SELECT @rownum:=@rownum + 1 as row_number, 
     t.* 
FROM ( 

select user_id, SUM(points) as Addedpoint 
from mytable group by user_id order by Addedpoint desc 

) t, 
(SELECT @rownum := 0) r 

Answer 3

select 
@rownum := @rownum + 1 AS position, 
user_id, 
total_points 

from 
(select user_id, sum(points) as total_points from table)a 
join 
(SELECT @rownum := 0) r 
order by total_points desc 

Answer 4

使用用戶變量，你可以做這樣的事情： -

SELECT user_id, tot_points, @Rank:=@Rank + 1 AS user_rank 
FROM 
(
    SELECT user_id, SUM(points) AS tot_points 
    FROM SomeTable 
    GROUP BY user_id 
    ORDER BY tot_points DESC 
) Sub1 
CROSS JOIN (SELECT @Rank:=0) Sub2 

Answer 5

可以實現與子查詢，在其內部應該算你的總和：

SELECT 
    @rank:=@rank+1 AS rank, 
    user_id, 
    total_points 
FROM 
    (SELECT 
    user_id, 
    SUM(points) AS total_points 
    FROM t 
    GROUP BY 
    user_id) AS sum_points 
CROSS JOIN 
    (SELECT @rank:=0) AS init 
ORDER BY 
    sum_points.total_points DESC 

-see my fiddle。

Answer 6

http://sqlfiddle.com/#!2/d0be9/1

SET @rank=0; 
select @rank:=@rank+1 AS rank, pointsScored.user_id, sumPoints 
from (
    select user_id , SUM(points)as sumPoints 
    from point 
    group by user_id 
    order by sumPoints desc 
)as pointsScored