Retrieve Object From Nested List Spring JpaRepository

Vlad Danila :

I do have a repository

public interface GroupRepository extends JpaRepository<Group, Integer> {
}

The Group does have a list of items

private List<Item> items;

Each Item has a position property

private int position;

How can I retrieve a group by knowing the position of an item present in one of the lists?

Item.java

public class Item extends PersistedBean{
 private int position;
 private Group group;

 @Column(name = "Position")
  public int getPosition() {
    return position;
  }

  @ManyToOne(fetch = FetchType.EAGER)
  @JoinColumn(name = "GroupId", referencedColumnName = "Id")
  public Group getGroup() {
    return group;
  }
}

Group.java

public class Group extends PersistedBean {
 private int position;
 private List<Item> items;

  @Column(name = "Position")
  public int getPosition() {
    return position;
  }

  @OneToMany(cascade = CascadeType.ALL, mappedBy = "group", orphanRemoval = false)
  public List<Item> getItems() {
    return items;
  }

}

Bartek :

You could add query to your JpaRepository<Group, Integer> repository, something like should work:

@Query("SELECT g FROM Group g " + 
       "JOIN g.items i ON i.position IN :p")
List<Group> getGroupsWhenPositionMatchAnyRelatedItem(@Param("p") Integer p);