ORA-00904 加入

Question

我正在尝试创建以下视图：

CREATE OR REPLACE VIEW AlbumDistribution AS
  SELECT Album.Album_ID,
         Album.title,
         HasTrack.tracked,
         FinishedTrack.released_title,
         SUBSTR(Album.Album_ID, -1) is_distributed_as
    FROM Album A
    JOIN HasTrack HT 
      ON HT.Album_ID = A.Album_ID 
    JOIN FinishedTrack FT
      ON HasTrack.OriginatesFrom = FT.OriginatesFrom
     AND HasTrack.tracked = FT.version;

但我收到 ORA-00904 错误：

 ERROR at line 6:
 ORA-00904: "HASTRACK"."TRACKED": invalid identifier

我觉得这很令人困惑，因为我之前引用了 HasTrack.tracked 并且没有错误。如果我更改语句的顺序，将 HasTrack.OriginatesFrom = FT.OriginatesFrom 放在最后，那么我会得到相同的错误，但对于 HasTrack.OriginatesFrom.

Answer 1

您为这个表和其他表定义了一个别名。您需要在整个查询中使用别名：

CREATE OR REPLACE VIEW AlbumDistribution AS
    SELECT A.Album_ID, A.title, HT.tracked,
           FT.released_title, SUBSTR(A.Album_ID, -1) is_distributed_as
    FROM Album A JOIN
         HasTrack HT
         ON HT.Album_ID = A.Album_ID JOIN
         FinishedTrack FT
         ON HT.OriginatesFrom = FT.OriginatesFrom AND
            HT.tracked = FT.version;

ORA-00904 加入

ORA-00904 on join

sql

oracle

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ora-00904