java spring data jpa，hibernate，奇怪的映射

Question

I have a little trouble with stange behavior of following. There are 3 entities: `

@Entity
@Table(name = "project")
public class Project {

@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;

@OneToMany(fetch = FetchType.EAGER, mappedBy = "project", cascade = CascadeType.ALL)
private List<Building> buildings; 

@Entity
@Table(name = "building")
public class Building {

@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;

@OneToMany(orphanRemoval = true, mappedBy = "building", fetch = FetchType.EAGER, cascade = CascadeType.ALL)
private List<GeoPoint> bound;

@ManyToOne
@JoinColumn(name = "project_id")
private Project project;
}

@Entity
@Table(name = "geo_point")
public class GeoPoint {

@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;

@ManyToOne
@JoinColumn(name = "building_id")
private Building building;
}

I porposly hid unnecessary fields and methods. I have some data in db storage and when i get data with repository method findAll() I recieve proper result.

But if I use the findOne() method of repository then I get 'weird' result, In this case number of Building increases and equals to number of GeoPoint. ie I have many duplicates of building.

Can you explain this behavior? Might be someone had similar issue.

edited:

The next result was received by invoking repository.findAll() method

 buildings: [{id: 1, osmId: 112896787, city: null, country: null, houseNumber: "5",…}] 0: {id: 1, osmId: 112896787, city: null, country: null, houseNumber: "5",…} bound: [{id: 1, longitude: 47.827211, latitude: 52.0166565},…] 0: {id: 1, longitude: 47.827211, latitude: 52.0166565} 1: {id: 2, longitude: 47.8270916, latitude: 52.0167423} 2: {id: 3, longitude: 47.8272374, latitude: 52.0168192} 3: {id: 4, longitude: 47.827502, latitude: 52.0169586} 4: {id: 5, longitude: 47.8277507, latitude: 52.0170896} 5: {id: 6, longitude: 47.8280161, latitude: 52.0172294} 6: {id: 7, longitude: 47.8282689, latitude: 52.0173626} 7: {id: 8, longitude: 47.8284111, latitude: 52.0174375} 8: {id: 9, longitude: 47.8285305, latitude: 52.0173517} 9: {id: 10, longitude: 47.827211, latitude: 52.0166565} city: null country: null houseNumber: "5" id: 1 osmId: 112896787 street: "Степная улица" description: "description" id: 1 latitude: 52.02038830745109 longitude: 47.826576232910156 name: "name" 

and invoking repository.findOne(id) method:

 buildings: [{id: 1, osmId: 112896787, city: null, country: null, houseNumber: "5",…},…] 0: {id: 1, osmId: 112896787, city: null, country: null, houseNumber: "5",…} bound: [{id: 1, longitude: 47.827211, latitude: 52.0166565},…] city: null country: null houseNumber: "5" id: 1 osmId: 112896787 street: "Степная улица" 1: {id: 1, osmId: 112896787, city: null, country: null, houseNumber: "5",…} bound: [{id: 1, longitude: 47.827211, latitude: 52.0166565},…] city: null country: null houseNumber: "5" id: 1 osmId: 112896787 street: "Степная улица" 2: {id: 1, osmId: 112896787, city: null, country: null, houseNumber: "5",…} bound: [{id: 1, longitude: 47.827211, latitude: 52.0166565},…] city: null country: null houseNumber: "5" id: 1 osmId: 112896787 street: "Степная улица" 3: {id: 1, osmId: 112896787, city: null, country: null, houseNumber: "5",…} 4: {id: 1, osmId: 112896787, city: null, country: null, houseNumber: "5",…} 5: {id: 1, osmId: 112896787, city: null, country: null, houseNumber: "5",…} 6: {id: 1, osmId: 112896787, city: null, country: null, houseNumber: "5",…} 7: {id: 1, osmId: 112896787, city: null, country: null, houseNumber: "5",…} 8: {id: 1, osmId: 112896787, city: null, country: null, houseNumber: "5",…} 9: {id: 1, osmId: 112896787, city: null, country: null, houseNumber: "5",…} description: "description" id: 1 latitude: 52.02038830745109 longitude: 47.826576232910156 name: "name" 

Answer 1

As I found out, this behavior is caused by issue of fetch annotation. If to add annotation @Fetch(value = FetchMode.SUBSELECT) it will work well.

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