CODEWITHSUNDEEP
jpa-2.0hibernate-mappinghibernate-onetomany
user820688
user820688

Reputation: 719

hibernate jpa join two table with another table

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,

Upvotes: 0

Views: 2663

Answers (2)

user820688
user820688

Reputation: 719

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

Upvotes: 0

mstzn
mstzn

Reputation: 2931

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;


}

Upvotes: 1

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