如何将行数据添加到第一次出现的字符串字段

Question

我发现了很多关于如何删除重复行的示例，但它们都涉及具有唯一整数ID的行。

这是我需要知道的。我想合并所有重复的字符串，并将其他列的值相加。

我有这样的：

stringID | v1 | v2 | v3 
    a | 2 | 3 | 4 
    b | 5 | 4 | 1 
    a | 1 | 1 | 2 
    b | 2 | 1 | 1 

我想这一点：

stringID | v1 | v2 | v3 
    a | 3 | 4 | 6 
    b | 7 | 5 | 2 

谢谢你的帮助。

编辑 我使用的是MySQL

Answer 1

我认为只是一个简单的GROUP BY和SUM()应该给你你要寻找的结果：

SELECT 
    StringID, 
    SUM(v1) AS v1, 
    SUM(v2) AS v2, 
    SUM(v3) AS v3 
FROM YourTable 
GROUP BY StringID 

See it in action with Sql Fiddle。

Answer 2

尝试......

select stringID, sum(v1), sum(v2), sum(v3) 
from yourtable 
group by stringID 

Answer 3

（免责声明：使用SQL-服务器> = 2005）

所以要与所有记录的总和先更新，那么你要删除的DUP：

更新：

WITH CTE AS 
(
    SELECT stringID, 
      v1_sum = SUM(v1) OVER (PARTITION BY stringID), 
      v2_sum = SUM(v2) OVER (PARTITION BY stringID), 
      v3_sum = SUM(v3) OVER (PARTITION BY stringID), 
      RN = ROW_NUMBER()OVER(PARTITION BY stringId Order By stringId) 
    FROM dbo.TableName 
) 
UPDATE tn SET v1 = v1_sum, v2 = v2_sum, v3 = v3_sum 
FROM CTE c 
INNER JOIN dbo.TableName tn ON c.stringId=tn.stringId 
WHERE c.RN = 1; 

删除：

WITH CTE AS 
(
    SELECT 
     RN = ROW_NUMBER()OVER(PARTITION BY stringId Order By stringId) 
    FROM dbo.TableName 
) 
DELETE FROM CTE WHERE RN > 1; 

DEMO