Home/ Questions/Q 7687473
In Process

The Archive Base Latest Questions

Editorial Team
  • 0
Asked: 2026-05-31T19:42:42+00:00

I have two entities A and B: A.java: … public class A implements Serializable

  • 0

I have two entities A and B:

A.java:

...
public class A implements Serializable {
private static final long serialVersionUID = 1L;
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Basic(optional = false)
@Column(name = "IDA", nullable = false)
private Integer ida;
@Basic(optional = false)
@Column(name = "NAME", nullable = false, length = 30)
private String name;
@OneToMany(cascade = CascadeType.ALL, mappedBy = "a")
private List<B> bList=new ArrayList();

public void addB(B bp){
bp.setA(this);
bList.add(bp);
}
...

B.java:

...
public class B implements Serializable {
private static final long serialVersionUID = 1L;
@EmbeddedId
protected BPK bPK;
@Basic(optional = false)
@Column(name = "NAME", nullable = false, length = 30)
private String name;
@JoinColumn(name = "A_IDA", referencedColumnName = "IDA", nullable = false, insertable = false, updatable = false)
@ManyToOne(optional = false)
private A a;
...

the bPK field is a Composite Primary Key:

@Embeddable
public class BPK implements Serializable {
@Basic(optional = false)
@Column(name = "IDB", nullable = false, length = 20)
private String idb;
@Basic(optional = false)
@Column(name = "A_IDA", nullable = false)
private int aIda;

public BPK() {
}

public BPK(String idb, int aIda) {
    this.idb = idb;
    this.aIda = aIda;
}
...

SQL code:

CREATE TABLE A (
idA INTEGER UNSIGNED NOT NULL AUTO_INCREMENT,
name VARCHAR(30) NOT NULL,
PRIMARY KEY(idA)
);

CREATE TABLE B (
idB VARCHAR(20) NOT NULL,
A_idA INTEGER UNSIGNED NOT NULL,
name VARCHAR(30) NOT NULL,
PRIMARY KEY(idB, A_idA),
FOREIGN KEY(A_idA)
REFERENCES A(idA)
  ON DELETE NO ACTION
  ON UPDATE NO ACTION
);

the main code:

   A a=new A(null,"A1");
   BPK bpk=new BPK();
   bpk.setIdb("b1");
   a.addB(new B(bpk,"B1"));

   EntityManager em=getEntityManager();
   em.getTransaction().begin();
   em.persist(a);
   em.getTransaction().commit();

I get this error:

 Exception in thread "main" javax.persistence.RollbackException: Exception  [EclipseLink-4002] (Eclipse Persistence Services - 2.3.0.v20110604-r9504):    org.eclipse.persistence.exceptions.DatabaseException
 [EL Warning]: 2012-03-26 01:29:16.724--UnitOfWork(1902320872)--Exception [EclipseLink-4002] (Eclipse Persistence Services - 2.3.0.v20110604-r9504):  org.eclipse.persistence.exceptions.DatabaseException
 Internal Exception: org.h2.jdbc.JdbcSQLException: Referential integrity constraint  violation: "CONSTRAINT_42_1: PUBLIC.B FOREIGN KEY(A_IDA) REFERENCES PUBLIC.A(IDA)"; SQL  statement:
 Internal Exception: org.h2.jdbc.JdbcSQLException: Referential integrity constraint   violation: "CONSTRAINT_42_1: PUBLIC.B FOREIGN KEY(A_IDA) REFERENCES PUBLIC.A(IDA)";...

the error indicates a violation of integrity constrains, but why?
a single possibility whether the insertion of the entity B is made before A…
Any help please?
Thank you in advance.

EDIT:
solved just replace this :

 @JoinColumn(name = "A_IDA", referencedColumnName = "IDA", nullable = false, insertable = false, updatable = false)

by this one:

 @MapsId("aIda")

finally B.java:

 @NamedQuery(name = "B.findByName", query = "SELECT b FROM B b WHERE b.name = :name")})
 public class B implements Serializable {
 private static final long serialVersionUID = 1L;
 @EmbeddedId
 protected BPK bPK;
 @Basic(optional = false)
 @Column(name = "NAME", nullable = false, length = 30)
 private String name;
 @MapsId("aIda")
 @ManyToOne(optional = false)
 private A a;
Share

Leave an answer

You must login to add an answer.

Need An Account,

1 Answer

  1. Editorial Team

    You have the A_AID field controlled by the aIda attribute in the Embeddable – that means this attribute must be set with the value from A before you can persist B.

    If you are using using JPA 2.0, you can mark the @ManyToOne with the @MapsId(“aIda”) which will allow you to remove the @JoinColumn for it. This will make the JPA provider set the value in b.bPK.aIda with the value from A on persist.

    If you are not using JPA 2,0, you can either set it yourself by first persisting A and then changing your addB method to also set B’s bPK.aIda, or you can change the fields so that the JoinColumn is writable and make the bPK.aIda insertable=false, updatable=false.

    • 0