如何應用SUM操作而不將結果分組到SQL中？

Question

我有這樣一個表：

+----+---------+----------+ 
| id | group | value | 
+----+---------+----------+ 
| 1 | GROUP A | 0.641028 | 
| 2 | GROUP B | 0.946927 | 
| 3 | GROUP A | 0.811552 | 
| 4 | GROUP C | 0.216978 | 
| 5 | GROUP A | 0.650232 | 
+----+---------+----------+ 

如果我執行下面的查詢：

SELECT `id`, SUM(`value`) AS `sum` FROM `test` GROUP BY `group`; 

我，很明顯，得到：

+----+-------------------+ 
| id | sum    | 
+----+-------------------+ 
| 1 | 2.10281205177307 | 
| 2 | 0.946927309036255 | 
| 4 | 0.216977506875992 | 
+----+-------------------+ 

但我需要像表這一個：

+----+-------------------+ 
| id | sum    | 
+----+-------------------+ 
| 1 | 2.10281205177307 | 
| 2 | 0.946927309036255 | 
| 3 | 2.10281205177307 | 
| 4 | 0.216977506875992 | 
| 5 | 2.10281205177307 | 
+----+-------------------+ 

總結行明確重複。

有沒有辦法獲得這個結果，而無需使用多個（嵌套）查詢？

Answer 1

這將取決於您的SQL服務器上，Postgres裏/ Oracle的我會用窗口功能。在MySQL中...不可能afaik。

也許你可以假像這樣：

SELECT a.id, SUM(b.value) AS `sum` 
FROM test AS a 
JOIN test AS b ON a.`group` = b.`group` 
GROUP BY a.id, b.`group`; 

Answer 2

沒有沒有AFAIK。你將不得不使用像

SELECT t.`id`, tsum.sum AS `sum` 
FROM `test` as t GROUP BY `group` 
JOIN (SELECT `id`, SUM(`value`) AS `sum` FROM `test` GROUP BY `group`) AS tsum 
    ON tsum.id = t.id