Question

我需要显示具有特定平均评分的电影列表。我知道问题出在HAVING子句中，但我不确定如何修复它。如果没有该子句，它就会起作用，它会列出所有遵循指定质量的电影/演员组合，但我需要它们的平均评分也高于4（这是我尝试使用having子句）。

使用HAVING子句，它表示ORA-30483：此处不允许使用窗口函数。有谁知道如何解决这个问题？

SELECT DISTINCT m.title "Movie Title",
   ROUND(AVG(r.rating) OVER (PARTITION BY m.movieid, a.actorid),2) "Average Rating",
   a.afname||' '||a.alname "Name",
   m.ryear
FROM netflix.actors a JOIN netflix.movies_actors ma
   ON a.actorid = ma.actorid
JOIN netflix.movies m
   ON ma.movieid = m.movieid
JOIN netflix.ratings100 r
   ON m.movieid = r.movieid
JOIN netflix.movies_genres g
   ON m.movieid = g.movieid
WHERE a.gender LIKE 'F'
   AND g.genrecode LIKE 'DRM'
   AND m.ryear >= TO_CHAR(SYSDATE, 'yyyy')-12
HAVING AVG(r.rating) OVER (PARTITION BY m.movieid, a.actorid) >= 4
ORDER BY "Average Rating" desc

Answer 1

仅在select语句中允许使用窗口或分析函数。所以你可以像这样过滤：

    select * from (
    SELECT DISTINCT m.title "Movie Title",
       ROUND(AVG(r.rating) OVER (PARTITION BY m.movieid, a.actorid),2) "Average Rating",
       a.afname||' '||a.alname "Name",
       m.ryear
    FROM netflix.actors a JOIN netflix.movies_actors ma
       ON a.actorid = ma.actorid
    JOIN netflix.movies m
       ON ma.movieid = m.movieid
    JOIN netflix.ratings100 r
       ON m.movieid = r.movieid
    JOIN netflix.movies_genres g
       ON m.movieid = g.movieid
    WHERE a.gender LIKE 'F'
       AND g.genrecode LIKE 'DRM'
       AND m.ryear >= TO_CHAR(SYSDATE, 'yyyy')-12


    ) as f1
    where f1.[Average Rating] >=4
ORDER BY f1.[Average Rating] desc

Answer 2

Google Analytics功能无法在WHERE或HAVING bloks中使用。他们在SELECT - 块中计算结果集。而且，如果没有HAVING，您也会使用GROUP BY，这也是一个错误。我认为您可以使用子查询和WHERE。

SELECT *
FROM
  (
    SELECT DISTINCT m.title "Movie Title",
       ROUND(AVG(r.rating) OVER (PARTITION BY m.movieid, a.actorid),2) "Average Rating",
       a.afname||' '||a.alname "Name",
       m.ryear
    FROM netflix.actors a JOIN netflix.movies_actors ma
       ON a.actorid = ma.actorid
    JOIN netflix.movies m
       ON ma.movieid = m.movieid
    JOIN netflix.ratings100 r
       ON m.movieid = r.movieid
    JOIN netflix.movies_genres g
       ON m.movieid = g.movieid
    WHERE a.gender LIKE 'F'
       AND g.genrecode LIKE 'DRM'
       AND m.ryear >= TO_CHAR(SYSDATE, 'yyyy')-12
  )
WHERE "Average Rating" >= 4
ORDER BY "Average Rating" desc

ORA-30483：这里不允许使用窗口函数？

2 个答案: