I get the following error when I do an update..

16:00:58,629 DEBUG [JDBCExceptionReporter] Could not execute JDBC batch update [update PAY set OPERATOR_DT=?, OPERATOR_ID=?, ACCOUNT_ID=?, AMOUNT=?, BATCH_ID=?, NOTE=?, CREATE_DT=?, INST_ID=?, IDNAME=?, STATEMENT_ID=?, STATUS_ID=?, EVENT_ID=?, EVENT_DT=?, PATIENT_ID=?, PLAN_ID=?, SCHEDULE_ID=?, STUDY_NUM=? where PAYMENT_ID=?]
java.sql.BatchUpdateException: ORA-01407: cannot update ("MY_SCHEMA"."PAY"."EVENT_DT") to NULL

at oracle.jdbc.driver.DatabaseError.throwBatchUpdateException(DatabaseError.java:343)
at oracle.jdbc.driver.OraclePreparedStatement.executeBatch(OraclePreparedStatement.java:10768)

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Classes >>

@Entity
@Table(name = "STATEMENT")
public class Statement extends DomainObject implements IPay
{
...
...
@OneToMany(mappedBy = "statement", cascade = { CascadeType.ALL })
@org.hibernate.annotations.Cascade(value = org.hibernate.annotations.CascadeType.DELETE_ORPHAN)
private final List<Payment> payments = new ArrayList<Payment();
...
...
}


@Entity
@Table(name = "PAY")
public abstract class Payment extends DomainObject
{
...
@Temporal(TemporalType.DATE)
@Column(name = "EVENT_DT", insertable = false, updatable = false)
protected Calendar eventDate = Calendar.getInstance();
...
@ManyToOne
@JoinColumn(name = "STATEMENT_ID")
private Statement statement;
...
...
}

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Any ideas what could be the issue?
As the error message indicates EVENT_DT column in table "PAY" is not nullable. Debugger shows there are valid values for event date. Therefore this must be a mapping issue.

Problem with -

remove

Then final annotation will be -