I'm trying to follow the JPA tutorial (en.wikibooks.org/wiki/Java_Persistence/ElementCollection#Example_of_an_ElementCollection_relationship_database) and using ElementCollection to record employee phone numbers:
PHONE (table)
OWNER_ID TYPE NUMBER
1 home 792-0001
1 work 494-1234
2 work 892-0005
Short version
What I need is a class like this:
@Entity
@Table(name="Phones")
public class PhoneId {
@Id
@Column(name="owner_id")
long owner_id;
@Embedded
List<Phone> phones;
}
that stores each person's phone numbers in a collection.
Long version
I follow the tutorial code:
@Entity
@Table(name="Phones")
public class PhoneId {
@Id
@Column(name="owner_id")
long owner_id;
@ElementCollection
@CollectionTable(
name="Phones",
joinColumns=@JoinColumn(name="owner_id")
)
List<Phone> phones = new ArrayList<Phone>();
}
@Embeddable
class Phone {
@Column(name="type")
String type = "";
@Column(name="number")
String number = "";
public Phone () {}
public Phone (String type, String number)
{ this.type = type; this.number = number; }
}
with a slight difference that I only keep one table. I tried to use the following code to add records to this table:
public static void main (String[] args) {
EntityManagerFactory entityFactory =
Persistence.createEntityManagerFactory("Tutorial");
EntityManager entityManager = entityFactory.createEntityManager();
// Create new entity
entityManager.getTransaction().begin();
Phone ph = new Phone("home", "001-010-0100");
PhoneId phid = new PhoneId();
phid.phones.add(ph);
entityManager.persist(phid);
entityManager.getTransaction().commit();
entityManager.close();
}
but it keeps throwing exceptions
Quote:Internal Exception: org.postgresql.util.PSQLException: ERROR: null value in column "type" violates not-null constraint Detail: Failing row contains (0, null, null). Error Code: 0 Call: INSERT INTO Phones (owner_id) VALUES (?) bind => [1 parameter bound] Query: InsertObjectQuery(tutorial.Phone1@162e295)
What did I do wrong?
] 
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