Hibernasi bergabung dengan dua tabel dan ambil semua catatan?

Anda perlu memikirkan objek Java saat menggunakan ORM alat.

Dari pertanyaan Anda, saya pikir kueri yang Anda coba tulis akan terlihat seperti:

public List<Category> getCategoryList(int id) {
    List<Category> groupList;
    Session session = sessionFactory.getCurrentSession();
    Query query = session.createQuery("select c from Category c join fetch c.events where c.parentCategory.categoryId = 1");
    //query.setParameter("id", id);
    groupList = query.list();
    return groupList;
}

Salah satu manfaat menggunakan ORM adalah ORM mengerjakan kueri gabung lengkap untuk Anda.

Agar ini berfungsi, Anda perlu memperbarui model kelas Anda sebagai berikut:

import java.io.Serializable;
import java.util.Date;
import javax.persistence.*;

@Entity
@Table(name = "events")
public class Event implements Serializable {

    private static final long serialVersionUID = 1L;

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "event_id")
    private int eventId;

    @Column(name = "event_name")
    private String eventName;

    @Column(name = "event_description")
    private String eventDescription;

    @ManyToOne
    @JoinColumn(name = "category_i")
    private Category category;

    @Column(name = "is_trending_event")
    private Integer isTrendingEvent;

    @Column(name = "image_url")
    private String imageUrl;

    private Integer status;

    @Column(name = "created_date")
    @Temporal(javax.persistence.TemporalType.DATE)
    private Date createdDate;

    @Column(name = "last_updated_date")
    @Temporal(javax.persistence.TemporalType.DATE)
    private Date lastUpdatedDate;

    ...

}

dan

import java.io.Serializable;
import java.util.Date;
import javax.persistence.*;

@Entity
@Table(name = "category")
public class Category implements Serializable {

    private static final long serialVersionUID = 1L;

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "category_id")
    private int categoryId;

    @Column(name = "category_name")
    private String categoryName;

    @ManyToOne
    @JoinColumn(name="parent_category_id")
    private Category parentCategory;

    @Column(name = "created_date")
    @Temporal(javax.persistence.TemporalType.DATE)
    private Date createdDate;

    @Column(name = "last_updated_date")
    @Temporal(javax.persistence.TemporalType.DATE)
    private Date lastUpdatedDate;

    @OneToMany(mappedBy="category")
    private List<Event> events;

    ...

}