Eclipse Community Forums: EclipseLink » Custom query to load list in bidirectional onetomany relationship

Help

Home

Home » Eclipse Projects » EclipseLink » Custom query to load list in bidirectional onetomany relationship

Show: Today's Messages :: Show Polls :: Message Navigator

Custom query to load list in bidirectional onetomany relationship [message #1778092]

Sat, 09 December 2017 19:06

Antonio Brea Mochales

Messages: 1
Registered: December 2017

Junior Member

I have a bidirectional onetomany relationship in this entities: Actividad and TagVinculado
TagVinculado entity has ManyToOne relationship with Tag
Tag entity has ManyToOne relationship with Tipo

When I access to tagsVinculados list from actividad entity, eclipselink create this queries:
1 query for tag_vinculados and for each tagVicnulado in list generetes 1 query for Tag and 1 query for Tag.Tipo
SELECT * FROM tags_vinculados WHERE (idActividad = ?)
SELECT * FROM tags WHERE (id = ?)
SELECT * FROM tipos WHERE (id = ?)
...
SELECT * FROM tags WHERE (id = ?)
SELECT * FROM tipos WHERE (id = ?)

Exist any way to custom the queries to load this list?
I would load this list with single query with 2 joins:
select tagVinculado
from TagVinculado tagVinc
inner join fetch tagVinc.tag tag
inner join fetch tagVinc.tag.tipo tipoTag
where tagVinc.actividad.id = ?

@Entity
@Table(name = "actividades")
public class Actividad Serializable {

@Column(name = "nombre")
private String nombre;

@OneToMany(mappedBy = "actividad", fetch=FetchType.LAZY, cascade = CascadeType.ALL, orphanRemoval = true)
private List<TagVinculado> tagsVinculados;
}

@Entity
@Table(name = "tags_vinculados")
public class TagVinculado implements Serializable {

@ManyToOne(fetch=FetchType.LAZY)
@JoinColumn(name = "idTag")
private Tag tag;

@ManyToOne(fetch=FetchType.LAZY)
@JoinColumn(name = "idActividad")
private Actividad actividad;
}

@Entity
@Table(name = "tags")
public class Tag Serializable {

@Column(name = "nombre")
private String nombre;

@ManyToOne(fetch = FetchType.LAZY)
@JoinColumn(name = "idTipo")
private Tipo tipo;
}

@Entity
@Table(name = "tipos")
public class Tipo Serializable {

@Column(name = "nombre")
private String nombre;
}

Report message to a moderator