从单一行中选择重复项？

在这里，我有一个表叫CoreTracks：从单一行中选择重复项？

+---------+-----------------+----------+----------+----------+---------+ 
| TrackId |  URI  | ArtistID | Title | FileSize | BitRate | 
+---------+-----------------+----------+----------+----------+---------+ 
| 1  | /home/music/... | 234 | atune | 8958223 | 192 | 
| 2  | /home/music/... | 427 | goodsong | 6954373 | 192 | 
| 3  | /home/music/... | 427 | goodsong | 4695698 | 128 | 
| 4  | /home/music/... | 427 | goodsong | 5839962 | 160 | 
| 5  | /home/music/... | 427 | goodsong | 4695698 | 128 | 
| 6  | /home/music/... | 522 | another | 3458859 | 128 | 
+---------+-----------------+----------+----------+----------+---------+

我想要检索的是：

+---------+-----------------+----------+----------+----------+---------+ 
| TrackId |  URI  | ArtistID | Title | FileSize | BitRate | 
+---------+-----------------+----------+----------+----------+---------+ 
| 3  | /home/music/... | 427 | goodsong | 4695698 | 128 | 
| 4  | /home/music/... | 427 | goodsong | 5839962 | 160 | 
| 5  | /home/music/... | 427 | goodsong | 4695698 | 128 | 
+---------+-----------------+----------+----------+----------+---------+

我试图消除基于具有相同的标题，同一艺术家ID重复，和不同的曲目ID，而不返回具有最高比特率和最高文件大小的条目。

我到目前为止是这样的：

SELECT * FROM CoreTracks 
WHERE Title = Title AND ArtistID = ArtistID 
AND BitRate != (SELECT MAX(BitRate) FROM CoreTracks WHERE Title = Title AND ArtistID = ArtistID) 
AND FileSize != (SELECT MAX(FileSize) FROM CoreTracks WHERE Title = Title AND ArtistID = ArtistID);

它返回每个轨道。我错过了什么使这个查询工作？

来源

2012-03-27 Brandon Minton

这会得到相反的（即跳过式两份）：

SELECT c1.* 
    FROM CoreTracks c1 
     ,(SELECT Title, ArtistID, MAX(FileSize) AS maxFileSize, MAX(BitRate) maxBitRate 
      FROM CoreTracks 
      GROUP BY Title, ArtistID) c2 
    WHERE c1.Title = c2.Title 
    AND c1.ArtistID = c2.ArtistID 
    AND (c1.FileSize = c2.maxFileSize OR c1.BitRate = c2.maxBitRate)

而重复：

SELECT c1.* 
    FROM CoreTracks c1 
     ,(SELECT Title, ArtistID, MAX(FileSize) AS maxFileSize, MAX(BitRate) maxBitRate 
      FROM CoreTracks 
      GROUP BY Title, ArtistID) c2 
    WHERE c1.Title = c2.Title 
    AND c1.ArtistID = c2.ArtistID 
    AND (c1.FileSize != c2.maxFileSize AND c1.BitRate != c2.maxBitRate)

来源

2012-03-27 00:54:58 Glenn

真不可思议。非常感谢！ – 2012-03-27 22:28:07

而不是选择重复的结果，我该如何去删除它们？ – 2012-04-05 04:05:36

@BrandonMinton你可以做一个“从CoreTracks WHERE TrackId中删除（SELECT c1.TrackId FROM ...） – Glenn 2012-04-05 11:32:21

从标题中选择max（trackId），ArtistID按BitRate asc排序 - 然后在由trackId选择的另一个选项中进行换行？

来源

2012-03-27 00:46:42

SELECT A.* FROM CoreTracks A, CoreTracks B 
WHERE A.Title = B.Title AND A.ArtistID = B.ArtistID AND A.trackId != B.trackId 
HAVING A.BitRate != MAX(A.BitRate) AND A.FileSize != MAX(A.FileSize);

尚未测试，但应该工作。

来源

2012-03-27 00:47:21 kasavbere

这看起来不错。我正在使用sqlite（我是新来的），它返回一个错误：“SQL错误：滥用聚合函数max（）”。 – 2012-03-27 01:07:14

尝试使用HAVING编辑版本：只需复制并粘贴。 – kasavbere 2012-03-27 01:12:06

另外如果你想永久删除，你可以用SELECT替换DELETE。 – kasavbere 2012-03-27 01:13:02

尝试自连接，而不是正常的查询。我没试过。

来源

2012-03-27 05:07:45

从单一行中选择重复项？

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