java - 无法持久化对象

Question

我正在尝试使用以下代码持久保存一个实体

public ReservationEntity persistReservation(ReservationRequest reservationRequest) {
    ReservationEntity re = new ReservationEntity();
    re.setTotalPrice(new BigDecimal(123));
    re.setFlightInstance(getFlightInstanceEntity(reservationRequest.getFlightId()));
    List<PassengerEntity> passengers = new ArrayList<>();
    for (Passenger p : reservationRequest.getPassengers()){
        PassengerEntity pe = new PassengerEntity();
        pe.setFirstName(p.getFirstName());
        pe.setLastName(p.getLastName());
        passengers.add(pe);
    }
    re.setPassenger(passengers);

    em.getTransaction().begin();
    em.persist(re);
    em.getTransaction().commit();

    return re;
}

乘客实体是

 @Entity
 @Table(name = "passenger", schema = "", catalog = "dbname")
 public class PassengerEntity {
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO, generator="passengerId")
     private int passengerId;
     private String firstName;
     private String lastName;
 // GETTERS-SETTERS


 }

@Entity
@Table(name = "reservation", schema = "", catalog = "dbname")
public class ReservationEntity {
    @Id
    @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "reservationId")
    private int reservationId;

    @OneToMany(fetch=FetchType.LAZY, cascade = CascadeType.PERSIST)
    @JoinColumn(name="passengerId")
    private List<PassengerEntity> passenger;
    public void setPassenger(List<PassengerEntity> passenger){this.passenger = passenger;}
    public List<PassengerEntity> getPassenger(){return this.passenger;}

我尝试过使用 GenerationType.AUTO 和 GenerationType.Sequence，在这两种情况下，我都收到了 table PassengerEntity.SEQUENCE 没有的错误存在 ( JPA EclipseLink DatabaseException: 'table foo.SEQUENCE doesn't exist' )

我尝试添加这些行，它实际上删除了我的整个架构和数据......

        <property name="eclipselink.ddl-generation" value="drop-and-create-tables"/>
        <property name="eclipselink.create-ddl-jdbc-file-name" value="createDDL_ddlGeneration.jdbc"/>
        <property name="eclipselink.drop-ddl-jdbc-file-name" value="dropDDL_ddlGeneration.jdbc"/>
        <property name="eclipselink.ddl-generation.output-mode" value="both"/>

这是我对该特定表的架构。该表有一个 FK 也有同样的问题。我试图首先坚持 parent ，然后是 child 。

CREATE TABLE `passenger`(
    `passengerId` INT NOT NULL AUTO_INCREMENT,
    `firstName` VARCHAR(45) NOT NULL, 
    `LastName` VARCHAR(45) NOT NULL,
    `reservationId` INT NOT NULL,
    PRIMARY KEY (`passengerId`), 
    INDEX `reservationId_idx` (`reservationId` ASC),
    CONSTRAINT `passenger_reservation_reservationId`
        FOREIGN KEY (`reservationId`)
        REFERENCES `reservation`(`reservationId`)
        ON DELETE NO ACTION
        ON UPDATE NO ACTION);

如果我将 GenerationType 更改为 GenerationType.IDENTITY 我会收到错误

javax.persistence.PersistenceException: Exception [EclipseLink-4002] (Eclipse Persistence Services - 2.5.0.v20130507-3faac2b): org.eclipse.persistence.exceptions.DatabaseException
Internal Exception: java.sql.SQLException: Field 'reservationId' doesn't have a default value
Error Code: 1364
Call: INSERT INTO dbname.passenger (FIRSTNAME, LASTNAME) VALUES (?, ?)
    bind => [2 parameters bound]
Query: InsertObjectQuery(com.project.entity.PassengerEntity@994)

将generator添加到实体并将类型更改为SEQUENCE后，我收到相同的错误

Internal Exception: java.sql.SQLException: Field 'reservationId' doesn't have a default value

Answer 1

@GeneratedValue(strategy=GenerationType.SEQUENCE, generator="columnName")
private int passengerId;

尝试用上面的代码注释你的passengerId