从嵌套列表中检索对象 Spring JpaRepository

Question

我有一个存储库public interface GroupRepository extends JpaRepository<Group, Integer> {}该组确实有一个项目清单private List<Item> items;每个Item都有一个position属性private int position;如何通过知道其中一个列表中存在的项目的位置来检索组 ？项目.javapublic 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;  }}组.javapublic 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;  }}

Answer 1

您可以将查询添加到您的JpaRepository<Group, Integer>存储库，类似于应该工作：

@Query("SELECT g FROM Group g " + 

       "JOIN g.items i ON i.position IN :p")

List<Group> getGroupsWhenPositionMatchAnyRelatedItem(@Param("p") Integer p);