In this section we look at how date and time is handled. If we want to persist a field of type java.util.Date we need to use the @Temporal annotation. This is described in the next subsection. The subsection "Queries with Date Parameters" shows how we handle a query with a java.util.Date or java.util.Calendar parameter. Finally the subsection "Datetime Functions" describes the date and time functions provided by JPQL.
Suppose we add a new field, dateOpened, of type java.util.Date in the Account entity. The dateOpened variable indicates the date on which the account was opened. We must use the @Temporal(TemporalType.DATE) annotation, which can be either field-based or property-based, to indicate that the field will be mapped onto the java.sql.Date database type. This is shown in the following code fragment:
@Entity
public class Account implements Serializable {
private int id;
private double balance;
private String accountType;
private Customer customer...