Question

我正在尝试加入三个表：

SELECT Songs.SongId,
Artist.ArtistFName,
Artist.ArtistLName,
Album.AlbumName,
Genre.GenreName, 
Songs.SongTrackNr,
Songs.SongName, 
Songs.SongDuration 

FROM
(((Album
INNER JOIN Songs ON Album.AlbumId = Songs.AlbumId)
INNER JOIN Ablum ON Album.ArtistId = Artist.ArtistId)
INNER JOIN Album ON Album.GenreId = Genre.GenreId);

但我得到的不是唯一的错误，我应该在Album表中放置别名吗？

由于

Answer 1

Ablum子句中有Album和FROM。我想你打算：

SELECT s.SongId, ar.ArtistFName, ar.ArtistLName, a.AlbumName, g.GenreName, 
       s.SongTrackNr, s.SongName, s.SongDuration 
FROM Album INNER JOIN
     Songs s
     ON a.AlbumId = s.AlbumId INNER JOIN
     Artists ar
     ON a.ArtistId = ar.ArtistId INNER JOIN
     Genre g
     ON a.GenreId = g.GenreId;

修复是表名。另外，请注意表别名 - 它们使查询更容易编写和读取。另外，FROM子句中不需要括号。

Answer 2

您可以使用以下查询，

SELECT Songs.SongId,
Artist.ArtistFName,
Artist.ArtistLName,
Album.AlbumName,
Genre.GenreName, 
Songs.SongTrackNr,
Songs.SongName, 
Songs.SongDuration 
FROM
Album Album
INNER JOIN Songs Songs 
ON (Album.AlbumId = Songs.AlbumId)
INNER JOIN Artist Artist
ON (Album.ArtistId = Artist.ArtistId)
INNER JOIN Genre Genre
ON (Album.GenreId = Genre.GenreId);

错误代码：1066。不是唯一的表/别名问题

2 个答案: