從單一行中選擇重複項？

在這裏，我有一個表叫CoreTracks：從單一行中選擇重複項？

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

我想要檢索的是：

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

我試圖消除基於具有相同的標題，同一藝術家ID重複，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條目。

我到目前爲止是這樣的：

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);

它返回每個軌道。我錯過了什麼使這個查詢工作？

來源

2012-03-27 Brandon Minton

這會得到相反的（即跳過式兩份）：

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)

而重複：

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)

來源

2012-03-27 00:54:58 Glenn

真不可思議。非常感謝！ – 2012-03-27 22:28:07

而不是選擇重複的結果，我該如何去刪除它們？ – 2012-04-05 04:05:36

@BrandonMinton你可以做一個「從CoreTracks WHERE TrackId中刪除（SELECT c1.TrackId FROM ...） – Glenn 2012-04-05 11:32:21

從標題中選擇max（trackId），ArtistID按BitRate asc排序 - 然後在由trackId選擇的另一個選項中進行換行？

來源

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);

尚未測試，但應該工作。

來源

2012-03-27 00:47:21 kasavbere

這看起來不錯。我正在使用sqlite（我是新來的），它返回一個錯誤：「SQL錯誤：濫用聚合函數max（）」。 – 2012-03-27 01:07:14

嘗試使用HAVING編輯版本：只需複製並粘貼。 – kasavbere 2012-03-27 01:12:06

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

嘗試自連接，而不是正常的查詢。我沒試過。

來源

2012-03-27 05:07:45

從單一行中選擇重複項？

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