Ebean：一对多关系的where子句

Question

我有两个模型 - 作者，书籍，如下所示。我想根据年龄查找有关作者的详细信息，并获取该作者撰写的所有未删除书籍。

作者

@Entity
@Table(name = "author")
public class Author extends Model {

    @Id
    @Column(name = "id")
    public int id;

    @Column(name = "name")
    public String name;

    @Column(name = "age")
    public int age;

    @OneToMany(mappedBy = "book", cascade = CascadeType.ALL)
    public List<Book> books;
    private static Finder<Integer, Author> find = new Finder<Integer, Author>(Integer.class, Author.class);

    public static List<Author> findByAge(int age) {
        return find.fetch("books")
            .where()
            .eq("age", age)
            .eq("books.isDeleted", false)
            .findList(); 

}

图书实体：

@Entity
@Table(name = "book")
public class Book extends Model {

    @Id
    @Column(name = "id")
    public int id;

    @ManyToOne(targetEntity = Author.class)
    @JoinColumn(name = "author_id")
    public Author author;

    @Column(name = "name")
    public String name;

    @Column(name = "is_deleted")
    public boolean isDeleted;
}

作者实体中的查找器有问题吗？我是否获取所有书籍，然后过滤 Java 中所有未删除的书籍？

提前致谢

Answer 1

我可以看到几个问题。您的模型应该扩展模型，并且您的书籍实体没有 isDeleted 字段（您可能想要一个 "public boolean deleted"，并将代码更改为 "books.deleted"，false）

除此之外，它看起来应该可行。

Ebean：一对多关系的where子句

Ebean: where clause on one to many relationship

java

playframework

one-to-many

ebean