Argthtjtr

I have Three table in which one table is using the foreign key of other two table to make the composite primary key. Now i am using the @Embeddable but as both the key are the foreign key, How i will create the composite primary key now in the Entity.

CREATE TABLE table1

(table1id INT NOT NULL AUTO_INCREMENT,

PRIMARY KEY (table1id));

table2

CREATE TABLE table2

(table2id INT NOT NULL AUTO_INCREMENT,

PRIMARY KEY (table2id));

table3

CREATE TABLE table3 (

   table1id INT NOT NULL,

   table2id INT NOT NULL,

   PRIMARY KEY (table1id, table2id),

   FOREIGN KEY (table1id) REFERENCES table1 (table1id),

   FOREIGN KEY (table2id) REFERENCES table2 (table2id)

);

How to convert this table into an Hibenate Entity.

 @Entity

 @Table(name="table3")

 class Table1 {

   @Id

   long table1id;

   //getter and setter

  }



 @Entity

 @Table(name="table3")

   class Table2 {

   @Id

   long table2id;

   //getter and Setter

   }



  @Entity

  @Table(name="table3")

  class Table3 {

     @EmbeddedId

     private table3PK table3PKId;



   //getter and Setter

   }





 @Embeddable

  Class table3PK{



  @ManyToOne

   @JoinColumn(name="table1Id" ,referencedColumnName="table1id")

  Table1 table1;



  @ManyToOne

  @JoinColumn(name="table2Id" ,referencedColumnName="table2id")

  Table2 table2;



  public table3PK(){



  }



  public table3PK(Table1 table1 ,Table2 table2){

   this.table1;

   this.table2;

  }





 }

}

It's not clear what problem you are encountering; but you might try using "derived identities" and mapping your entities like this:

@Entity

public class Table1 {

    @Id

    long table1id;

    // ...

}



@Entity

public class Table2 {

    @Id

    long table2id;

    // ...

}



@Embeddable

public class Table3PK {

    long table1PK; // corresponds to PK type of Table1

    long table2PK; // corresponds to PK type of Table2

} 



@Entity

public class Table3 {

    @EmbeddedId

    private Table3PK id;



    @MapsId("table1PK") // maps table1PK attribute of embedded id 

    @ManyToOne

    Table1 table1;



    @MapsId("table2PK") // maps table2PK attribute of embedded id 

    @ManyToOne

    Table2 table2;



    // ...

}

Derived identities are discussed (with examples) in the JPA 2.2 spec in section 2.4.1.