How to persist data using JPA concatenated key in the @Manytomany relationship?

Question

I have the first entity

private static final long serialVersionUID = 2405172041950251807L;

private static final String CAMPO_CODIGO = "CODIGO";

@Id
@GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "SEQ_TABLE1")
@SequenceGenerator(name = "SEQ_TABLE1", sequenceName = "SEQ_TABLE1", allocationSize = 1)
@NotNull
@Column(name = "CODIGO")
private Long codigo;

@Column(name = "table1Field1")
private Short table1Field1;

@Column(name = "table1Field2")
private String table1Field2;

@Column(name = "table1Field3")
private Long table1Field3;

@OneToMany(
    mappedBy = "table1",
    cascade = {CascadeType.PERSIST, CascadeType.MERGE, CascadeType.REMOVE},
    orphanRemoval = true
)
private List<RelTable1Table2> relTable1Table2 = new ArrayList<>();

The other entity

@Id
@GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "SEQ_TABLE2")
@SequenceGenerator(name = "SEQ_TABLE2", sequenceName = "SEQ_TABLE2", allocationSize = 1)
@NotNull
@Column(name = "CODIGO")
private Long codigo;

@Column(name = "table2Field1")
private String table2Field1;

@Column(name = "table2Field2")
private Short table2Field2;

@OneToMany(
    mappedBy = "table2",
    cascade = CascadeType.ALL,
    orphanRemoval = true
)
private List<RelTab1Tab2> relTab1Tab2 = new ArrayList<>();

And the entity that relates the two entities.

private static final long serialVersionUID = 2405172041950251807L;


@Id
@ManyToOne(fetch = FetchType.LAZY)
@JoinColumn(name = "CODIGO_TAB_2", referencedColumnName = "CODIGO")
private Table2 table2;

@Id
@ManyToOne(fetch = FetchType.LAZY)
@JoinColumn(name = "CODIGO_TAB_1", referencedColumnName = "CODIGO")
private Table1 table1;

Class doing creates id for relationship entity

private Long table1;

private Long table2;

What is the correct way to enter and update the data present in these three tables, using the resources of jpa ? The principle is being done like this

private void persisteEatualiza(Table1SaveData table1SaveData){


    Table1 table1 = table1Mapper.toEntity(table1SaveData.getTable1());
    List<Table2> table2s = table2Mapper.toEntity(table1SaveData.getTable2());
    List<RelTab1Tab2> relTab1Tab2s = new ArrayList<>();
    for(Table2 table2 : table2s){
        RelTab1Tab2 relTab1Tab2 = new RelTab1Tab2();
        relTab1Tab2.setTable2(table2);
        relTab1Tab2.setTable1(table1);
        relTab1Tab2s.add(relTab1Tab2);
    }
    table1.setRelTab1Tab2(relTab1Tab2s);
    table1Repository.save(table1);

Answer 1

I think we’re missing an entity. In the case of concatenated key you need a class to be only the key and the actual entity will have this key.

@Embeddable
class EntidadeChave implements Serializable {

    @Column(name = "tabela1_codigo")
    Long tabela1Codigo;

    @Column(name = "tabela2_codigo")
    Long tabela2Codigo;

    // construtores, getters, and setters
}

---

@Entity
class relacaoEntidates{

@EmbeddedId
EntidadeChave id;

@ManyToOne
@MapsId("tabela1_codigo")
@JoinColumn(name = "tabela1_codigo")
Tabela1 tabela1;

@ManyToOne
@MapsId("tabela2_codigo")
@JoinColumn(name = "tabela2_codigo")
Tabela2 tabela2;

//outras colunas;

//construtores, getters, and setters
}

---