sql服務器分組結果

Question

此查詢返回它下面的列表，但是ID出現了多次，我可以將ID分組並匯總所有播放嗎，所以我只是得到一個唯一ID列表，其旁邊是播放總數。 在SQL這可能嗎？

SELECT [fkPlayerId],[plays]
FROM [dPlaysPerDay]
INNER JOIN dWinners
ON [dPlaysPerDay].[fkPlayerId]=dWinners.[pkWinnerId]

53693   1
53695   1
53696   1
53693   1
53692   2
53698   2
53697   1
53699   2
53698   3
53693   6
53699   2
53693   2
53700   2
53698   1

Answer 1

使用GROUP BY ， SELECT中的所有數據項必須包含在GROUP BY或放置在Aggregate Function中 。

因此， fkPlayerId應分組，和plays與所使用的SUM()函數

SELECT [fkPlayerId], SUM([plays])
FROM [dPlaysPerDay]
INNER JOIN dWinners ON [dPlaysPerDay].[fkPlayerId]=dWinners.[pkWinnerId]
GROUP BY fkPlayerId

要對聚合函數進行ORDER BY ，請給數據項一個別名，並按以下順序排序：

SELECT [fkPlayerId], SUM([plays]) as TotalPlays
FROM [dPlaysPerDay]
INNER JOIN dWinners ON [dPlaysPerDay].[fkPlayerId]=dWinners.[pkWinnerId]
GROUP BY fkPlayerId
ORDER BY TotalPlays