查询列中的房间错误 return

Question

我见过这个问题但我无法将其应用到我自己的错误中。

这是我的Movieclass

    @Entity
    public class Movie {

        @PrimaryKey
        @NonNull
        public String id;

        @ColumnInfo
        public String name;

        @ColumnInfo
        public String title;
    }

这是我的UpcomingMoviesclass

@Entity(
        foreignKeys = {
        @ForeignKey(
                entity = Movie.class,
                parentColumns = "id",
                childColumns = "movieId")
        },
        indices = @Index("movieId")
)
@TypeConverters(MovieConverter.class)
public class UpcomingMovies {

    @PrimaryKey(autoGenerate = true)
    public int id;

    @ColumnInfo
    public int movieId;

    @ColumnInfo
    public Movie movie;
}

我正在尝试运行的查询，我想获取电影列表

@Query("Select movie from UpcomingMovies")
LiveData<List<Movie>> loadUpcomingMovies();

以及我遇到的具体错误

error: The columns returned by the query does not have the fields [id] in *.Model.POJOs.Movie even though they are annotated as non-null or primitive. Columns returned by the query: [movie]

我在这里错过了什么？

编辑：已添加 MovieConverter

public class MovieConverter {

    @TypeConverter
    public String movieToString(Movie movie) {
        return new Gson().toJson(movie);
    }

    @TypeConverter
    public Movie stringToMovie(String src) {
        return new Gson().fromJson(src, Movie.class);
    }
}

Answer 1

试试这个查询：

@Query("Select * from UpcomingMovies")
LiveData<List<UpcomingMovies>> loadUpcomingMovies();

并且在你的 UpcomingMovies class 中有一个 GETTER 方法：

public Movie getMovie() {
    return this.movie;
}

您还可以使用此查询获取电影列表：

@Query("Select * from Movie")
LiveData<List<Movie>> loadUpcomingMovies();

祝你好运:)

查询列中的房间错误 return

Room error in query columns return

android

android-room

android-livedata