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我的理解是,一個單向一對多關係有一個連接表,而一個雙向一對多關係沒有。Java EE - 一對多雙向
我的應用程序工作時,我實現了單向關係,但我似乎無法讓它工作的雙向關係。
這些都是我創造
CREATE TABLE CUSTOMER (customerNo INTEGER PRIMARY KEY, joinDate DATE, customerName VARCHAR2(20));
CREATE TABLE BOOKING (bookingNo INTEGER PRIMARY KEY, bookedDate DATE, custNo INTEGER, itemNo NUMBER(10), itemName VARCHAR2(20), quantity NUMBER(5), bookingDate DATE, bookingValue NUMBER(8, 2), constraint booking_fk foreign key (custNo) references customer(customerNo));
我的第一類
public class Booking implementes Serializable{
private Timestamp bookeddate;
private Timestamp bookingdate;
@Id()
@GeneratedValue(generator"MY_SEQ_GEN")
@SequenceGenerator(name="MY_SEQ_GEN", sequenceName="MY_SEQUENCE", allocationSize=1)
@Column(name="bookingNo", nullable=false)
private Long bookingno;
private Double bookingvalue;
@Column(length = 20)
private String itemname;
private Long itemno;
private Long quantity;
private Customer customer;
@ManyToOne
public Customer getCustomer() {
return customer;
}
...
我的其他類的表
public class Customer implements Serializable {
@Column(length = 20)
private String customername;
@Id()
@GeneratedValue(generator="THE_SEQ_GEN")
@SequenceGenerator(name="THE_SEQ_GEN", sequenceName="THE_SEQUENCE", allocationSize=1)
@Column(name="customerNo", nullable=false)
private Long customerno;
private Timestamp joindate;
@OneToMany(cascade=(CascadeType.ALL), fetch=FetchType.EAGER, mappedBy = "customer")
private List<Booking> bookings = new ArrayList<Booking>();
public List<Booking> getBookings() {
return bookings;
}
我的豆倒下後,我跑這個方法
public void addBooking(Long custno, Long tickno, Long quantity) {
Customer cust = (Customer) em.createNamedQuery("findCustomerByPrimaryKey").setParameter("eid", custno).getSingleResult();
Booking b = new Booking();
b.setBookeddate(new Timestamp(System.currentTimeMillis()));
b.setCustomer(cust);
b.setTicket((Ticket) em.createNamedQuery("findTicketByPrimaryKey").setParameter("eid", tickno).getSingleResult(), quantity);
cust.addBooking(b);
//persistBooking(b);
}
這是我的錯誤消息。
javax.ejb.EJBException: BEA1-001D72BA69DC9E472B1E: Local Exception Stack:
Exception [EclipseLink-4002] (Eclipse Persistence Services - 2.0.2.v20100323-r6872): org.eclipse.persistence.exceptions.DatabaseException
Internal Exception: java.sql.SQLSyntaxErrorException: ORA-00904: "CUSTOMER_CUSTOMERNO": invalid identifier
Error Code: 904
Call: INSERT INTO BOOKING (bookingNo, ITEMNAME, BOOKINGDATE, BOOKINGVALUE, ITEMNO, QUANTITY, BOOKEDDATE, CUSTOMER_customerNo) VALUES (?, ?, ?, ?, ?, ?, ?, ?)
bind => [71, Metallica, 2011-01-05 22:07:17.788, 200.0, 420, 2, 2011-01-05 22:07:17.788, 1526]
Query: InsertObjectQuery([email protected])
at org.eclipse.persistence.exceptions.DatabaseException.sqlException(DatabaseException.java:324)
at org.eclipse.persistence.internal.databaseaccess.DatabaseAccessor.executeDirectNoSelect(DatabaseAccessor.java:801)