hibernate jpa join two table with another table

Question

I have two table A and B

Table A:

ID_A

name

table B

ID_B

name

I joined both by a third table C table with their primary key

table C

ID_C

ID_A

ID_B

I'd like to know this relationship in jpa mapping to retrieve the list of object B inside object A

thank you,

score 1 · Answer 1 · answered Oct 09 '12 at 15:29

Class A has list of C objects.

class A{

@Id
private Long Id;

@Column(name = "name_a", length = 5)
private Strin name_a;

@OneToMany(cascade = CascadeType.ALL, mappedBy = "a", fetch = FetchType.LAZY)
private List<C> cList;
}
class B{

@Id
private Long Id;

@Column(name = "name_b", length = 5)
private String name_b;

@OneToMany(cascade = CascadeType.ALL, mappedBy = "b", fetch = FetchType.LAZY)
private List<C> cList;

}

This is join table.Class C has A object and B object.

class C{

  @Id
  private Long id;

  @JoinColumn(name = "id_a", referencedColumnName = "id", nullable = false)
  @ManyToOne(optional = false, fetch = FetchType.LAZY)
  private A a;


  @JoinColumn(name = "id_b", referencedColumnName = "id", nullable = false)
  @ManyToOne(optional = false, fetch = FetchType.LAZY)
   private B b;


}

Thanks for response, this is correct but what i want us to have sommethong like private List bList; inside object A, is this possible, wow to do to map this ? — user820688, Oct 09 '12 at 15:37
it is imposible that you want because of relationship between A and B.And I think it is not necessary — mstzn, Oct 09 '12 at 17:31

score 0 · Accepted Answer · answered Oct 10 '12 at 09:19

0

I have find a good example here http://viralpatel.net/blogs/hibernate-many-to-many-annotation-mapping-tutorial/

answered Oct 10 '12 at 09:19

user820688

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hibernate jpa join two table with another table

2 Answers2