spring - How to add Columns from Junction table to the Child - Stack Overflow

admin管理员组

文章数量:1208155

I am working with Spring Boot JPA Hibernate. I have @ManyToMany relationship and Junction Table. One Entity is called Entity and the other Button. And then Junction Table is called ENTITY_BUTTONS

This Junction Table has some additional Columns. When I get a List of Button Children I would also like these additional columns to be included. But I am not sure how to do that.

So basically I don't want just a list of children but list of some other structure that will contains columns from the child and additional Columns from Junction Table for that Child relation.

My goal is to just be able to get top Entitiy and then that all the other entities and their children are automatically picked up in a complete hierarchy.

@javax.persistence.Entity
@Table(name = "ENTITIES")
public class Entity {

    @ManyToMany(fetch = FetchType.LAZY)
    @WhereJoinTable( clause = "active = true and is_deleted = false")
    @JoinTable(
        name               = "ENTITY_BUTTONS",
        joinColumns        = @JoinColumn(name = "ENTITY_ID"),
        inverseJoinColumns = @JoinColumn(name = "BUTTON_ID")
    )
    private List<Button> buttons;

}


@Entity
@Table(name = "BUTTONS")
public class Button  { ... }

I am working with Spring Boot JPA Hibernate. I have @ManyToMany relationship and Junction Table. One Entity is called Entity and the other Button. And then Junction Table is called ENTITY_BUTTONS

This Junction Table has some additional Columns. When I get a List of Button Children I would also like these additional columns to be included. But I am not sure how to do that.

So basically I don't want just a list of children but list of some other structure that will contains columns from the child and additional Columns from Junction Table for that Child relation.

My goal is to just be able to get top Entitiy and then that all the other entities and their children are automatically picked up in a complete hierarchy.

@javax.persistence.Entity
@Table(name = "ENTITIES")
public class Entity {

    @ManyToMany(fetch = FetchType.LAZY)
    @WhereJoinTable( clause = "active = true and is_deleted = false")
    @JoinTable(
        name               = "ENTITY_BUTTONS",
        joinColumns        = @JoinColumn(name = "ENTITY_ID"),
        inverseJoinColumns = @JoinColumn(name = "BUTTON_ID")
    )
    private List<Button> buttons;

}


@Entity
@Table(name = "BUTTONS")
public class Button  { ... }

• spring
• hibernate
• relationship
• boot

Share Improve this question Follow edited Jan 20 at 13:01 ivoronline asked Jan 20 at 12:46 ivoronlineivoronline 1,07922 gold badges1111 silver badges2424 bronze badges

Add a comment  | 

1 Answer 1

Sorted by: Reset to default 0

I believe that you need to replace the ManyToMany with a pair of OneToMany on the explicitly defined Entity EntityButton.

@javax.persistence.Entity
@Table(name = "ENTITY_BUTTONS")
public class EntityButton {

    @EmbeddedId
    EntityButtonId entityButtonId;

    String anotherAttribute;

    String anotherAttribute2;
}

@javax.persistence.Entity
@Table(name = "ENTITIES")
public class Entity {

    @OneToMany(fetch = FetchType.LAZY)
    private List<EntityButton> entityButtons ;

}

@Entity
@Table(name = "BUTTONS")
public class Button  {     
    @OneToMany(fetch = FetchType.LAZY)
    private List<EntityButton> buttonEntities ;
    
 }

@Embeddable
public class EntityButtonId {
    private String entityId;
    private String buttonId;

}

To access the additional association table columns you will need to use JPQL, eg:

@Query("select eb.anotherAttribute, b.buttonAttrib from EntityButton eb JOIN eb.buttons b on eb.buttonId = b.buttonId where eb.entityId = :entityId")

本文标签： springHow to add Columns from Junction table to the ChildStack Overflow