CODEWITHSUNDEEP
javahibernatejpa
Gokul Kulkarni
Gokul Kulkarni

Reputation: 2259

Hibernate inverse join for composite primary key

I am new to hibernate.

I have the following situation,

@Entity(name="A")
Class A {
   @Id
   int id;

   Set<B> listB;
}

@Entity(name="B")
Class B {
   @Id
   CompositebPK bPk;
}

Class CompositebPK {
   @Column(name="id")
   int aId;
   @Column(name="user_name")
   String uname;
}

@Entity (name = "user")
Class User {
   @Column (name ="user_name")
   String uname;
}

table Structures is as follows,

Table A:
int id

Table B:
int id
String uname

User:
String uname
String password

A to B is 1 to many relation. B to User is 1 to many.

I want to have the list of B's in A.

What is the best approach to solve the situation?

In the net when I search I am just getting information for inverse join for simple columns, if I try that its not working out, so is there a special way to achieve this?

Upvotes: 1

Views: 1699

Answers (1)

M A
M A

Reputation: 72884

Try the following mapping configuration:

In the A entity class:

@Entity(name="A")
class A {
   @Id
   int id;

   @OneToMany(fetch = FetchType.LAZY, mappedBy = "bPk.a")
   @Cascade(value = { CascadeType.DELETE })
   Set<B> listB;
}

In CompositebPk:

class CompositebPK {
   @ManyToOne(fetch = FetchType.LAZY)
   @JoinColumns({ @JoinColumn(referencedColumnName = "id", nullable = false) })
   A a;
   @Column(name="user_name")
   String uname;
}

Upvotes: 1

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