Avoiding second lazy fetch query

Hibernate ORM
1

Entity Code:

@Entity
@Table(name = "videos", indexes = { ... })
public class Video {

    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "uploader_id")
    private Channel channel;

}

@Entity
@Table(name = "channels", indexes = { ... })
public class Channel {

    @Id
    @Column(name = "uploader_id", length = 30)
    private String uploader_id;

}

The problematic code:

Session s = ...;
System.out.println(s.createNativeQuery(
                "select videos.*, channels.* from videos left join channels on videos.uploader_id = channels.uploader_id",
                Video.class).getResultList().get(0).getChannel());

The problem is that two queries are created when doing this! This is done by enabling show_sql in the properties.

Hibernate: 
    select
        videos.*,
        channels.* 
    from
        videos 
    left join
        channels 
            on videos.uploader_id = channels.uploader_id
Hibernate: 
    select
        channel0_.uploader_id as uploader1_0_0_,
        channel0_.uploader as uploader2_0_0_,
        channel0_.uploader_avatar as uploader3_0_0_,
        channel0_.verified as verified4_0_0_ 
    from
        channels channel0_ 
    where
        channel0_.uploader_id=?

Is there any way to only use one query? I’ve been able to do this when using the criteria api, but my query I want to write would be too complex for the criteria api.

2

Hi,

what is it that you are trying to do that you think you can’t do with the Criteria API? It’s quite powerful, so it should be possible. Anyway, what you described here can be done with a Hibernate API as shown in the documntation: Hibernate ORM 5.5.7.Final User Guide