已知影片评论数据库包括如下表结构:Movie ( mID, title, year, director )影片表,属性包括影片编号,影片名,发行年份以及导演。Reviewer ( rID, name )评论者表,属性包括评论者编号,评论者姓名。Rating ( rID, mID, stars, ratingDate )评论表,属性包括评论者编号,影片编号,评分(1-5),评论日期。基于该数据库完成以下SQL题目。要找出对同一部电影评论次数在3次及以上的评论者姓名,下列语句不能实现该功能的是( )
选项:
A:select name from reviewer,rating where reviewer.rid=rating.rid group by reviewer.rid having count(stars)>=3;
B:select name from reviewer A where (select count(stars) from rating B where
A:rid=
B:rid group by rid)>=3;
C:select name from reviewer where (select count(stars) from rating where reviewer.rid=rating.rid)>=3;
D:select name from review,rating where reviewer.rid=rating.rid and count(stars)>=3 group by reviewer.rid
发布时间:2024-05-19 14:36:36