我不知道为什么我不能得到 movie
领域。我调试了一下,找到了 movie
为空。我贴了张照片,你会看到的
. 请给我一些建议。我确信我已经成功地建立了这段关系,但我的推荐可能有问题。上课还是上课?
public interface MovieRepository extends GraphRepository<Movie> {
@Query("match (user:User {login: {0}})-[r:RATED]->(movie)<-[r2:RATED]-(other)-[r3:RATED]->(otherMovie) "
+ " where r.stars >= 3 and r2.stars >= r.stars and r3.stars >= r.stars "
+ " with otherMovie, avg(r3.stars) as rating, count(*) as cnt"
+ " order by rating desc, cnt desc"
+ " return otherMovie as movie, rating limit 10")
List<MovieRecommendation> getRecommendations(String login);
}
推荐.class
@QueryResult
public class MovieRecommendation {
Movie movie;
int rating;
public Movie getMovie() {
return movie;
}
public void setMovie(Movie movie) {
this.movie = movie;
}
public int getRating() {
return rating;
}
public void setRating(int rating) {
this.rating = rating;
}
}
控制器
@RequestMapping(value = "/user", method = RequestMethod.GET)
public String profile(Model model, HttpServletRequest request) {
HttpSession session = request.getSession(false);
User user = (User) session.getAttribute("user");
model.addAttribute("user", user);
if (user != null) {
List<MovieRecommendation> mr = movieRepository.getRecommendations(user.getLogin());
MovieRecommendation movie = new MovieRecommendation();
Movie m = new Movie();
m.setTitle("AA");
movie.setMovie(m);
mr.add(movie);
model.addAttribute("recommendations", mr);
}
return "user/index";
}
运行cypher使用neo4j社区
match (user:ollie)-[r:RATED]->(movie)<-[r2:RATED]-(other)-[r3:RATED]->(otherMovie)
where r.stars >= 1 and r2.stars >= r.stars and r3.stars >= r.stars
with otherMovie, avg(r3.stars) as rating, count(*) as cnt
order by rating desc, cnt desc
return otherMovie limit 10
1条答案
按热度按时间fcwjkofz1#
我认为您的查询返回null。
所以第一个元素[0]有一个空的电影。。。
电影“aa”应该在数组的[1]中,因为您进行了查询并在查询之后附加了推荐