如何在不将结果分组到SQL的情况下应用SUM操作？

Question

我有一张像这样的桌子:

+----+---------+----------+
| 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 | 
+----+---------+----------+

如果我执行以下查询:

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

我显然得到:

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

但我需要一个像这样的表:

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

其中明确重复求和的行.

有没有办法在不使用多个(嵌套)查询的情况下获得此结果？

Answer 1

IT将依赖于您的SQL服务器,在Postgres/Oracle中我会使用Window Functions.在MySQL ...不可能afaik.

也许你可以像这样伪造它:

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`;